Although this is indeed CPF tradition, I don't see this condition currently listed in OP.
The following excerpt is worth a look ...
State your terms of sale clearly. The clearer your terms are, the less likely it will be that problems will occur with your sale. Take the time to look at a few sale threads by experienced sellers, and see how they do it. You should specify:
Item description – make it accurate, and post a picture if possible
What the buyer must post in order to close the deal: for example, the first "I’ll take it"
Any trades or "parting out" of items you will consider – and how you will prioritise part sales
What form of payment you will accept (Paypal, money order, credit card, other - specify) ....
The original post (prior to editing in some additional details after prompting) lacked several of the above items.
The reasons for these suggestions are evident from the collective experience here on the MarketPlace.
Still, it is OP's sale to run, as they will.
A request, for OP - please return, to clarify and update thread
Another request, for others - please refrain from negative commentary or "thread-trashing"