Don't judge a book by it's cover... But actually do judge your book by it's cover, because without an intruiging cover, your book won't sell well.
And that's why you are going to have to be willing to pay a bit more for your book cover. If you only pay $30 for a book cover, odds are it won't look to great, and your book won't sell well. But if you hire a proffesional and get a good book cover, it will sell. A great place to find book cover designers is Fiverr, as well as Deviant Art. Those sites are loaded with artists, and are pretty affordable.
There is another site, called Deranged Doctor Designs or DDD, which does book covers for indie authors- and their covers are AMAZING. Of course, because they look so good, the book covers are around $100 more expensive than good covers on Fiverr. (So about $360)
But if you save up for a good cover, it will definetly pay off in the end.
Here are the links to the websites. I hope they help!
https://www.fiverr.com/?source=top_nav
https://www.derangeddoctordesign.com/
https://www.deviantart.com/