The marketplace fee is a percentage of profit that is taken out of all items that are sold for Robux on ROBLOX. This fee helps support the ROBLOX economy as well as keep the supply of ROBUX consistent.
The marketplace fee has always been a percentage taken out of the profit that you make on your products. It was implemented when users first began to make and sell their own clothing and was established at an amount of 10%. Later, when the Limited items system came out, the fee for Clothing remained at 10%, and the fee for Limited items was established as 25%.
On July 25, 2012, ROBLOX changed the marketplace fee for all items to a 30% fee. They did this in an attempt to regulate the ROBUX that came into the economy, making it easier for users to estimate their income.
When you sell an item, many times you want to know exactly how much profit you are going to make. The Marketplace Fee seems to get in the way of this; unless you use a little bit of basic algebra to figure out the amount you have to sell the item for to make a certain profit.
The formula for how much profit you make from a sale is described below, where p is the profit and x is the amount you are selling it for:
p = x - .3x
Now, let's say you want to make a profit of 100 ROBUX. How much do you sell the item for? To find this out, plug 100 in for p and use Algebra to figure out the value of x.
100 = x - .3x 100 = .7x --1x - .3x = .7x 142.9 = x -- divide both sides by .7 x = 143 --Round to nearest whole number
This means that if you want to make a profit of 100 ROBUX, you have to sell the shirt for 143 ROBUX.
The marketplace fee for those without a Builders Club membership is seen as heavily excessive by some users in comparison to what players who do have a Builders Club membership have to pay (90% tax for NBC users as opposed to the 30% tax for BC users).