Agreed. When I first started I purchased a quite a few appraisals myself. The appraisals were probably as realistic as any such appraisals are -- which is to say the amounts were plausible in the event of a sale and consistent with pricing elsewhere. But actual offers and sales don't correlate much with those appraisals, in my experience. I've sold above and below those amounts, and most of the appraised domains are still on the shelf with no viable offers. That's to be expected, since appraisals are instantaneous dollar amounts whereas sales depend on long-term probabilities. The main point is that I quickly reverse-engineered the appraisers methodology, so that I could predict basically the same amounts they were selling me. Actually I found that what they were doing was very crude. My money is better spent elsewhere, and I expect the same will be true for you. Pay attention to domain sales and pricing for awhile, ask other people what they think, list your domains for sale long enough to get some (or not get any) offers ... and you'll get a better sense of domain market realities than you would by paying for an arbitrary number.
There is really no credible and universal domain appraisal methodology yet. With real estate appraisals, the appraiser has some financial liability and faces some risks that incentivize accuracy. That isn't true of the domain industry and may never be. Domains are very heterogeneous and very volatile, and nobody knows with any surety what a domain will sell for or when.