Typically you won’t have real people harvesting emails for sale - it’s much easier to get addresses in bulk by hacking services and dumping their databases - and you get password hashes as well, which makes it a much better value proposition for the time it takes.

Off the top of my head, a couple of things that it could be:

• Simple stolen card fraud - buy something small with a stolen credit card to prove it works before using it for a higher value purchase. Something where you don’t need to worry about a physical product getting delivered somewhere would be great for this
• Escrow fee fraud - commission something small, then use that as a hook to promise a much larger commission, except that they want to use some off-site service to “reduce the fees”, then “oops the money has been flagged as maybe fraudulent and you need to pay a fee to get it released”
• Money mule recruitment - again, small commission (using a stolen card) to establish a relationship, then come to you with a great job opportunity where they will send you some money via western union or something, and all you need to do is send it on to someone else, and you get to keep a cut. The catch is you are actually handing stolen funds or helping someone evade international sanctions, and you end up in prison

Here, let me pay you $700 for this item that’s worth $500 and you can just send me the extra $200 difference. I have to do it this way because it’s your father’s, brother’s, nephew’s, cousin’s, former roommate’s will and I’m just signing the whole check off to you.

Meanwhile the original check is fake and now you’ve lost the original item AND $200 and the bank is investigating you, and not them.

In the 2000s I worked in IT and we hosted a spam filter. Back then people would send out seemingly harmless email, about Jack’s golf game or the picnic on Sunday, and their goal was to build up their domain’s reputation as a legitimate sender. Then one day they’ll send out spam and it’ll get through the filter until the spam filter catches on and cuts off that domain.

IMO if the scam angle isn’t obvious, it’s probably pig butchering.

But if the message specifically says they want to buy something from you, I’d be more inclined to guess that it’s some form of refund scam, or maybe a con specifically targeting people with a side hustle.

Pretty much every form of these scams is some kind of advance fee fraud. Two more possible avenues:

• “Upgrade to a business account”. They send you an email purporting to be from the payment provider you used saying you need to upgrade to business to receive a payment that large, and the upgrade page is a fake website run by the scammer that asks for a “refundable deposit” or the like (with a little helping of credit card fraud and of course a business account will require all kinds of personal info useful for identity theft too).
• “But I want it as an NFT” was popular for a bit, they want you to “pre-pay the minting fee but it’s ok I’ll add it to your payment” and then they disappear. But they want it on a website ran by them and the moment you put the crypto in they disappear. Not sure this scam is popular nowadays because NFT screams scam to just about everyone for a lot of different reasons. But “rich guy spends $5000 on dumbass NFT” was a legitimate genre of news for a little moment.

It’s all preying on someone that thinks they got an easy paycheck for work that they’ve already done, on a populace of artists that could really use said paycheck to pay for food and are thus willing to overlook weirdness or principles. They also tend to pick on newer and younger artists that haven’t quite figured out how to run a business yet, hoping that they haven’t heard of scams specifically targeted to their sector.

It’s just bots bypassing bot filter. Most platforms now restrict activity of new user accounts to combat spam, so bot farms create new accounts, create some spam posts, wait two-three months until these accounts become unrestricted, then post some political ads en masse.