An option to limit sales on your assets/games/creations.
This would serve basically as an exclusive certain amount for sale type thing.
For example... I have a game script that I only want to sell say.. 1 of to a lucky person then the BUY button will be removed from the sale page.
This could be set by the seller when setting up the item's sale page by ticking the box... Limit Item [person would type number in box] once the number is reach in sales the 'Buy Now' button will get removed so no more can be sold unless the item seller puts another amount in the box again, if it's left blank then no one can buy more. The items page would remain still though so people can look at the item.