Don't you just hate it when you post an item and then find out that somebody posted exact same one for 1g less? This can get very annoying sometimes , specially if the item you post is hard to sell/you don't have gold for re post .

I though it would be nice implement a minimal price difference of ~10% . How this will work :

Player A posted an item to Cs for 1.000.000 gold
Player B has the same item and wants to sell it .
10% of 1m makes 100k so the minimal difference in price will be +/- 100k .

( I know this might be hard to code in , just giving an idea )