Suspicious buyers, what is the angle?

So I have this domain name robot.earth, listed at another site. I will be listing more here because this place seems real, so I'll ask a real question. I've been through one domain sale in the past, and it was a large one. I found a couple buyers, they bid each other up, I ended up finding a broker who lived in Portugal to finalize it all, which prob helped being a noob, and got paid through Escrow.com. it was great.

It's been years since. Someone contacts me about robot.earth, offers me five figures, a bit above a high price I had placed on it, because it's appraised value is 2-3k max probably, though it is a good name, but it's still a weird TLD. So I don't want to get in the way of this sale, and trying to do what the customer wants rapidly. They want to get paid through Quickbooks payments, which is a legit biz site, but they don't care how I'm going to get them the domain. 'We'll handle it after you invoice
my friend".

So I set up a QB account, not having one already. I tell him I want to know the registrar I'm transferring to and an email, because I want to deliver this domain name ASAP after payment. He sends me - Godaddy (suprising not) and an email. I call Godaddy, and they have no email, no business name I've been given, none of it. So then the party in my head ends.

QB claims they don't do refunds on their payments system. Debates are settled by the parties. I never sent out the invoice because I don't want to get into some debate about inconsistencies with a scammer, though I certainly wanted the sale. The email he gave me is attached to a domain not commonly used, though it is a common word - accountant.com. There's some company called world.com "company accelerator" this name is owned by. They seem to have a long list of seriously valuable straight domain names - for sale, or maybe just to sign email addresses to, I have no idea. So that part of the story kind of checks out, but not really, because literally anyone can prob get an email on one of these domains. Plus that world.com site is super opaque in its intent. Pretty odd stuff.

So I tell the guy I need a functioning email at the host to transfer to, or use escrow.com and he tells me that they wanted to spend six figures on this and other domains, but there's too much back and forth and his 'friend' is losing patience, classic scam talk. We've literally been in regular correspondence 4 days after the initial start with gaps on both sides. Since when is domain selling a second by second activity?

So I guess I'm just wondering how this con works, is it just weird incompetent buyers (doubt it). They're not supposed to be able to get bank numbers through QB which filters them out. Why bother with this approach, except maybe to claim they didn't get what they paid for, and start making my life difficult. It really ticks me off also, the arrogance mixed with the cluelessness, but that's the type to pull something like this. They are using a gmail account (with a single number at the end). I have half a mind to report it, but if these are nefarious types, prob better just to wave bye.