Limited item

Limited is a label given to catalog items available in finite quantities. They are initially regular items sold by for a set price until they are taken off-sale, and if the item is later selected to become Limited then they may be traded for other items or re-sold for Robux by those who have an active Builders Club membership.

Concept
Limited items are classed as 'collectibles' by Roblox, which means that multiple copies of a specific Limited item can be attained and stored in a user's inventory. They are a quintessential part of the trading system, and in practice function quite similarly to tradable and/or sell-able items in other virtual economies such as the Steam Community Market. Limited items can be quite volatile in their values, e.g. one day the Beautiful Hair for Beautiful Space People could be worth 3,040 Robux in RAP and the next day go down to 2,792 (this type of volatility also depends on how highly demanded the Limited item is, its stability, and how many copies of it are in circulation).

Limited unique
Limited unique (LimitedU) items are those which are sold in specific quantities with a fixed price upon release and immediately become available for resale or tradable once sold out, compared to limited items which generally go off-sale as regular items until they are manually selected to become limited. There are also serial numbers attached to the item depending on when the item was purchased. Limited unique items are often seen as more valuable than regular limited items, and this is amplified by demand for certain serial numbers which also signify when the unique copy was purchased from ROBLOX (#1, #42, #1337, etc.).

Release times
The ROBLOX account is most often expected to publish new limited unique items during a weekend and when specific hours begin. However, there will not always be new limited unique items when a weekend arrives.

Criticism
Many have complained about the use of bots to purchase limited unique items much earlier than regular users can. This is commonly a problem with items having lower stock (the most notable example of this being the Immortal Swords).

Rare
Users consider an item rare when it has a low stock (usually less than 100 copies in existence). Although some items may sell for a high price, they may not be considered valuable because it has low demand (which is due to the incredibly high price). Due to the low stock, the recent average prices (also known as RAP) may be low, and the item is thus perceived of less value. Rare items are the most expensive items in the catalog and the reason for their low RAP is because hardly any copies of them are ever sold.

High demand
A limited with high demand is wanted by a large number of people, which is why many of these items have moderate stocks but are worth considerably more than you would expect. These types of limiteds commonly sell daily and have ascending prices. An item can be high demand mostly when it has a high stock and is bought several times a day.

Projected
A limited that is projected is intentionally sold for a very high price while the RAP dramatically rises extremely high. They mostly vary with low stock (around 10,000 or less) and are not sold as much by users. Once a limited is projected, it will start to sell under RAP due to the unexcepted price change and rapidly descend to its original selling price and RAP. These limiteds are not as favored by the community and are considered to be 'foul' or 'scamming' items, although some may attempt to take advantage of the price illusion.

Poisoned
A poisoned item is one that has been stolen from a user's account. These items contain the risk of the owner being banned without awareness. They are not commonly traded around but can be traded for without notice. Bans from harboring a poisoned item can be appealed, but it depends if the owner intentionally or unintentionally traded for the item (often judged by whether they offered lower or higher value in RAP for the item).

Market
Although limited items follow the general rule of supply and demand, many players still dislike this because of instances like an item being sold for 50 Robux rising to 50,000 in a short span of time. Some players also criticize limited items because there may not be any resellers of certain items, making it impossible to obtain them even though they aren’t actually off-sale. This issue is exacerbated by 'hoarders', a term used to describe users who buy or trade for a high quantity of a specific Limited item in order to take those copies out of circulation with the end goal of increasing the item's value to be resold or traded at a profit.

In terms of the market, price-warring is an issue with Limited items. A price war initially consists of a player wanting to sell their Limited item, so they put it up for sale at the cheapest price. Then, another player wants to sell their copy of that Limited item so they put theirs up for an even cheaper price. This results in the first user becoming agitated and taking their item off the market, then putting it up again with a price that is usually 1-10 less Robux than the second person. A loop of undercutting then ensues until one person gives up and stops lowering their prices. This behavior is criticized because it hinders people from selling their items and is also quite toxic. These usually happen to high demand items.

Trading
As with all online games that have trade systems, there are users who seek illegitimate gains through scamming. Since Roblox introduced trading in 2012, there have been many deceptive tricks that users have employed (such as the infamous ‘double-trade’ scam) in order to con others out of their limiteds.

In some cases, malicious users may obtain a poisoned limited on purpose and attempt to quickly trade it off to someone else with the intended result of the recipient being terminated. Users have called on Roblox to be more careful when reviewing these incidents.

Permanent removal
Roblox has sometimes removed limited items from terminated players’ inventories, even though they are already considered to be deleted forever when the user is initially terminated. This is often for players that use the "One Time Rollback" feature. One known example was in 2016; due to  getting compromised several times and ContentCool purchasing his ‘stolen’ limiteds, almost all of ContentCool's items were taken after his termination. Since Roblox does not manually resell or redistribute a terminated player's limiteds, they are essentially gone forever and this has led to concerns from many users because of the effects on the limited economy as well as the site's history.

Trade bots
Trade bots are known in the trading community for being a "havoc"  Many players have criticised them for sending constant "horrible" trades in groups at a certain time. Players also have criticised the Roblox team for doing nothing to stop the issue, despite being years after the trade bots. Currently, there are 159 active trade bots as of May 2, 2019. A quick solution to solving the trade bot issue is to set your trades to followers instead of everyone.

Trivia

 * Spam_Sold.png users with at least 10 copies or more of the same limited item may spam the "Private Sales" section of the limited item's page, with each copy usually costing the same price.
 * When a user purchases a limited item, it will appear next to the last item the user bought after it became a limited item.
 * Although users can only purchase one copy of a limited unique item per account while it is still in stock, some have used methods to purchase more than one on the same account. These accounts are usually banned by Roblox shortly afterward.