I have found a fantastic site, called Paper and Sage – Book cover designers which designs pre-made and custom covers and I am going to rave about it!
The price is amazing, $50 – $70 for an ebook cover. You can change the typography I think for free if they have used it already on another cover.
The covers look professional, and, one of my big bugbears about self-pubbed books, they do not look less than a proper published cover. You will look like a professional!
They do other design things for you which will help with branding/promotion etc.
Bookmark this site people!!