A writer publishing ebooks is at a great advantage these days concerning ebook covers, in that, most of the book sellers allow you to upload a cover any time you like.
Don't listen to people who place more emphasis on an 'eye catching cover' than they do on a work itself. If you like simple covers, then make a simple one. You can usually find a way to make a simple one for free. If you decide later you want a more creative one, change it. All the while, perhaps you will have gained a few readers and sold a few copies to friends and family who simply bought it because you wrote it.
Most of the advice I hear concerning ebooks is about sales. The medium seems to favor long term plans. You can always do something with what you have now and market it later when you have a better visual. Perhaps you enjoy simple covers altogether. Stay true to yourself and don't get caught up in sales.