The best thing to do is to meet at the bank. Ask the buyer to deposit money into your account. This is very quick if the banks are same. You get instant posting of credits to your account.
If the banks are different ask him to bring cash and deposit it in his presence. People even use fake currency.
If the amount is too big to carry simply open an account in his bank which hardly takes a few minutes and ask him to transfer online.
There is no trustworthy method besides these.
Luckily you decided to get it verified. PO once considered safe are prone to conterfeit these days. Aj kal cheque/PO ka zamana ni.