Advice for you:You should lower the prices for your banners.
Usually people would pay for that much if the banners were made from an actual program (like Photoshop), not a website.
I don't want to say anymore.
But just trust me.. I've had the banner making experience, plus I've been around here longer.
I know you want to make the tu for whatever reason, I understand, but you should take a different approach (I can't help with that though).
I apologize if I come off as mean/rude, I really don't mean to.