There are plenty of post out there on this subject and here's one more. If you don't think your book cover is important then you are selling yourself and your book short. I went back and forth over simple or striking for days, probably weeks before I decided what route to take.
I knew what I really wanted. I wanted that reader to look at my cover and say WOW! So what was the next step. Do it myself? Maybe, but that's not what I decided. It took me awhile but my search was worth it. After perusing the internet I discovered Deviantart (great place) and found my cover artist, Char Marie.
After a few emails and chats we were on the same page and the results were amazing. What a great person to work with. The cover has drawn so many to my book that it is amazing. I have even had people who don't read fantasy tell me the cover peaked their interest and once inside the pages they were glad it did.
So, how important is that cover? It might be the most important step you take, second to writing your book. If you would like that kind of interest go see what Char has to offer.