And that's just the beginning. You'll need to establish written policies and procedures for all aspects of the business, train your client's employees in regards to appraisal procedures, establish compliant levels of security (kiss yahoo and gmail bye-bye), levels of review, establish authorization levels for your clients (who may order/cancel/place on hold, dispute value, request corrections, request updates, ETAs, etc.), payment procedures, procedures to grade and track turn times, who will pull SSRs, who will handle FHA numbers and VA ordering, track appraiser performance and appraisal report quality in a way that can be audited, and you will likely have to hire a CPA to keep your financials in order. After all of that (and more) don't assume that secondary market and other investors will just accept AIR certifications, etc. from a random startup AMC, you will likely have to qualify with them. And last but not least, you may have a good relationship with the mortgage brokerage now, but when it's crunch time and the fingers start pointing you're the guy that will be in the middle of it all with them yelling at you to get that late report in now, handle "low" values, get silly stips/corrections in, have that impossible property appraised, deal with corrupted XML files, deal with non-responsive appraisers, deal with buybacks, etc.
Edit, forgot to add: What will you do when an appraiser complains about undue influence, AIR violations, etc? Or when a LO demands you kick an appraiser off of the panel? What products will you handle (VCs, Evals, PCRs, field reviews, etc.) along with pricing.
Or you can just wing it and hope for the best (not suggesting that you would but more than a few are).
