I'm inclined to concur w/ beemk and 4pics. A decent sponsor hosted gallery should bring in more than this.
This is essentially pay per impression rates for a pay per click program.
I'm still confused about the gallery itself, is this or is this not remotely hosted?
Regarding tracking, You could always pass this through some tracking variable w/ your trade script or some counter cgi then fight about it later on
I still think I could find a use for this... I would at least try it out, but it won't be the best traffic... unfiltered stuff on various misc. pages...