Well, B&S do carry such risks. My lesson learnt was I will insist on having his/her hp number as i will give mine, too. Sometimes, it is good to have some conditions (as in transaction T&C) as it helps sieve out the bad buyers/sellers.
If there are such buyers, there will also be such sellers. So it is not always the buyers at fault. Quite afew of my friends gotten fake sandisk cards already. One of my friends even bought a stack of fake 8gb sandisk cards. No show is only a small loss to you. Try to get over it.