I can only tell you what I know it costs in my personal experience, but for me an exotic animal vet visit is usually in the $50-65 range, and then any eye ointments they prescribe are usually no more than $15-20.
That's usually enough to treat a minor issue. But if he really needs antibiotics on top of that then I've paid more like $30-40 for my oral antibiotics.
I usually expect to pay about $80-100 for a minor chameleon issue, basically, unless I am lucky enough to get the vet visit on the house.