Diminished Value Appraisal process questions

I was rear-ended a few months ago. When I got my car back, the body shop recommended a DV appraiser to get a lot more money back than the at-fault insurance initially paid me. I've never heard of this process, but it sounded like a great idea. I started the process with them. Their flat fee is $450 for the report, and they estimated they could get me $4000+ back.

When they asked about vehicle history, I truthfully told them about some prior comprehensive claims. In June of this year, I filed a claim for hail damage ($4000 paintless dent repair), and in March of this year, I filed a claim to replace the roof glass after it cracked ($3000 repair). In 2021, a mirror flew off a truck and hit my car. I don't remember the amount of this repair, but they replaced the bumper and a fog light. I had never done a DV appraisal for any of these, just accepted the insurance-offered DV payment. I am only interested in claiming DV for the most recent accident, as it is using the at-fault insurance. I'm not interested in filing DV for my comprehensive claims for fear of my premiums going up, probably not worth it in the long run.

We went back and forth on this for a while, but in the end, the appraiser is saying they need to do 3 separate appraisals (rolling the 2021 claim into one of them), and that they could do it all for $1000 (and I assume that $4000+ return is going to shrink also). Is this a standard process, or is this guy taking advantage of me? He's pretty highly rated and very experienced, but this is giving me shady vibes.

I ended up paying the $1000 through Venmo (the only payment service they accept that has some consumer protections), I checked the box for "goods and services," and the owner sends me an extremely unprofessional text blaming me that Venmo took $30 of fees out of his $1000 payment. That's when my frustration really boiled over towards this guy, and I haven't spoken to them in a couple days while I cool down.

Venmo issue aside, am I being taken advantage of by this multiple report process or is this standard practice for a DV appraisal?

Details:

• State: GA
• Car: 2020 Tesla Y
• Claim #1: Aug 2025, Rear-ended, $9,000 repair
• Claim #2: Jun 2025, Hail, $4,000 repair
• Claim #3: Mar 2025, Roof glass, $3,000 repair
• Claim #4: Dec 2021, Mirror strike, $3-5,000 repair? Incident in FL, reside in GA still