As ever,
If you have to start a thread on STW asking “is this a scam?” the answer is “yes.”
Whilst generally I’d agree, I had one a while back that made me ask but turned out it wasn’t.
Guy wanted to buy something, agreed a price, then they wanted to pay by cheque.
Bounced cheque liely I thought but seemed genuine. I agreed but said I’d delay postage until X days after (whatever they say is the time to properly clear, not just show in the account).
Anyway a few days later, a cheque with a nice handwritten note appears and all went very smoothly.
Not really a lesson there other than protect yourself with the process, but don’t assume unusual requests are always a scam.