No way would I ever settle for such greed, and if artists are prepared to do that then they have only themselves to blame.  If you're good you'd likely be better off setting up your own exhibition than stand for crap like that.

Without wanting to sound rude, I honestly think that any person who accepts less for their own work than the third party gets out of it, must have some sort of mental illness.  Either that or a complete lack of self-respect.  Seriously, if you do that then you are a "product" and they own you even though you did the work.

Peoples attitudes really need to change.  In general,  art dealers have always been parasites, but these days you can avoid them altogether thanks to the internet, you know what I mean?

Click for a lesson on how to deal with Greedy Art Dealers
(It's old, and better than you might think).