The issue for any commissioned project is time. Custom artwork takes a lot of time to create. First, coming up with ideas, then sketching/drafts, then back and forth with the buyer, then rough draft, then changes, then full colorization/mock-up, then more changes, then finally working to the final product.

I would say to do a full cabinet $3000 is about right (that about 30 hours of effort at $100/hr). Remember, this is a self-employed job, so that $100/hr gets double taxed from the seller's perspective.

A more economical approach would be to find some available artwork that is already out there and can be used as is or with some minor tweaks. Are you familiar with this site? https://imgur.com/a/MhlPm#0