I've started sending screenshots of one scammer to the other and chatting with them. They're very persistent and will attempt to de-risk by offering to "pay you back." I pointed out to one that my concern was the credit card skimming, they just ignored it and continued on the reimbursement track.

Never mind I've gotten 5 other messages exactly like yours. Oh, you trust your site more than CarFax, and you want to make sure you're not being ripped off. You didn't even haggle! I'm so unreasonable refusing to use this service to pay for a report for you.

Sure random out-of-state phone number, I'll put my credit card info into this URL/random site name you told me to Google on the chance you might buy my shit. What could possibly go wrong? I'm sure that random site is totally legit and you totally aren't running it and storing all card info.