Random Unthreadworthy Questions
I think its incumbent upon the prospective buyer A to send a PM immediately after posting in thread.
By all means call dibs or ask questions in thread but business should get transacted via PM IMHO.
As a seller I’m not necessarily checking my own FS thread every time I open TGR but PM’s pop up a notification. Had one instance where I tried to sort out priority via via time stamps on thread posts vs PM’s - would not bother again.
In your scenario do whatever the hell you like, sell to whomever you want and blame it on the TGR forum software.
Random Unthreadworthy Questions
Is anyone really going to post payment email and shipping address in the FS thread?
Fundamental question is who is responsible for shifting discussion to private communication?
If I put up a FS flyer old school style on a lamppost or notice board with little tabs to rip off with phone number should a prospective buyer just wrote their number on it and say call me hoping I’d wander back by to check?
Maybe Buyer A is a 2 post jong and not able to pm yet in which case you already know what to do.
Or wait a few minutes while I check your posts to see what this hot FS item is and if I want it - calling dibs right here right now just incase.
Edit - I checked, fact pattern in play here, not even a dedicated FS thread originated by you. PM priority all day long IMHO but now you opened the can of worms here so YMMV.