I'd suggest incorporating if you are serious and it's easy to do in your jurisdiction. I haven't used it, but Stripe Atlas is an option that is meant to make this easy.
Another option is to draw up some kind of contract with a price and payment terms (i.e. 30 days after you invoice).
Now, if you can get them to agree to this, you have at least a month, potentially two, before they even try to pay you. Long enough to decide if it is worth your time working out how to collect the payment.
Running the payment via another LLC is probably going to be awkward for them tax wise. Most jurisdictions allow for sole traders and you can probably use your personal account for now if that seems easier.
Disclaimer: I am not a lawyer or accountant. This is for entertainment purposes only ;-)