Don't think you need custom cover art? You might want to think again.
As with any business (and yes your band is a business) you try and find out where you can save money. I am advising not to settle for a generic album identity and to budget for a custom cover. Your cover is really an album identity. To promote your album you should use that same design for a Facebook skin, t-shirt design, set design, possible new website design and more. Building a solid brand identity is crucial for success in this modern market, and your cover becomes the visual identity of your music.