Buyers set the market, not sellers. Sellers can hold on their figures, and hope the a buyer comes along. Supply and demand I think are the two most important factors.
This isn't always true. There are plenty of things that are exclusive to the individuals/organizations/regions that are selling them. There are also instances where individuals corner the market on an item(s) and then demand their price point. Sure it's up to the buyer to decide whether they want to spend it. But if someone wants or needs something bad enough, and buying from this entity is the only feasible way, then there is little choice to be had.
And about your Claw going for $5 bucks on eBay jest. Well plenty of Rare Muscles have gone for a $1 or less on eBay due to being overlooked. IE: The purple claw being disputed in this topic. The Puzzle Man SR went for a Buck as well. So it happens if the item isn't specifically showcased. eBay is like that entity that corners the market on Muscle Rares though. It's unlikely to find one otherwise, and thus if properly showcased the value will always remain the same due to demand (probably ever regardless of supply, like SC).
Edited by Universal Ruler Supreme, 15 July 2011 - 12:41 PM.