Agree with all the above.
It does beg the question - when do you change an item to SOLD? When someone has said they'll have it, or when you've received the payment...
Personally, I do the latter.
Either can be a pain though - mark as SOLD & then lose potential buyers if the original 'buyer' doesn't pay, or receive a load more PMs wanting the item in the period before payment is received. Then have to send loads of replies saying "it's awaiting payment - will get back to you tomorrow if 'buyer' doesn't pay" (as I do) or ignore them & upset RobW, etc