I have passed on many a deal because the initial contact didn't pass the smell test... I usually will pass on any seller that demands or requests certified funds as I find that to be too much to the benefit of the seller and a sign of immediate distrust towards the buyer. (I did make my first EVER exception this week to purchase a gun off of a well respected forum member here, so like Ruger, I guess I can never say never!).
To me, when I offer to send a personal check with the caveat that the seller can hold "as long as he is comfortable or necessary to clear", then, that should be acceptable payment and most sellers will accept my check. I will NEVER wire money or deal with someone that is a newbie. I have seen a huge increase in scams on Armslist, to the point where I am just about done even looking at that site.
I am suspicious by nature, I would not have responded to his PM because of the use of simple, common names, i.e Tim/Ben and the lack of last names...no last name is a flag to me on the FIRST contact.
I have gotten some great buys off eBay because of NEW sellers not being established but that is usually small dollars and I am accepting the risk before I bid/buy.
Caveat Emptor, Baby!
Please let us know how this turns out for you....