Why cant we just sell an item for say 10,000 and get 10,000?
would you sell a house for someone as a broker/agent and not get any fee for doing it ? that is how it works in swtor it's called commission
if you want the whole 10k use the trade channel and spam the items for hours and hours on end, I know what option I would use.
The difference is that this is a game and first and foremost it is supposed to be fun.
While I do see the point in having a deposit to discourage spamming of ridiculous junk items that won't sell, if you add in fees and taxed and the math starts getting so complicated that you need a calculator or spreadsheet formula to figure out how much you are going to get it stops being fun and starts being annoying and confusing.