Ouch. That sounds high, high, HIGH!! When I don't make my own covers with Photoshop on my computer, I go to Dvorak Designs,
http://www.dvorakdesigns.com. I'm working on children's books using my three Persian cats, and the covers are less than $50.00 each, with much work involved. That sounds really high -- what your costs are. Hope this info. helps. Calibre is great, too, if you want to make different formats. Feel free to contact Preston at Dvorak Designs, if you like.