When should you buy cover art?

When I first started this journey of writing, I never expected to self-publish. I thought I was going to submit Always & Forever to a publisher and keep trying until I landed a contract. I never figured I would make the decision to completely forgo submitting anything to anyone. Yep, that's right. I never even tried for a rejection slip. I'm still of the belief that I could probably get a contract, especially with all the smaller publishers available for romance titles. I really...