because its an industry standard. Its not illegal to go "looks like everyone else is charging 30%, let's charge the same). And in general, you don't have an inc

because its an industry standard. Its not illegal to go "looks like everyone else is charging 30%, let's charge the same). And in general, you don't have an incentive to undercut on price in a situation like this since nobody wins a price war - you try to bring some other value to justify listing on your platform (like a captive audience). Its easiest to just go with whatever ends up being the industry standard- and these prices are all public, no secret information has to be shared to see what everyone else is doing.