FWIW, I bought my Wee from a Stromtrooper member. I view any used purchase as a done deal, believing that a dealer might feel even more inclined to tell you to go pound sand, so I did my best on it beforehand and placed a bit of weight on the fact that the Previous Owner was here.
I assume that any Strom has been bashed in some fashion or other. Mine had a skid plate, crash bars, Pro Tapers and Barkbusters on it. The PO did say what wrong with the bike and what maintenance would need to be done soon. I got pictures beforehand, asked him some questions, and then drove to pick it up - but it was a day's ride away.
I did not ask for a pre-purchase inspection w a compression and blow-down test because I can fix most anything that goes wrong. (If you don't feel comfortable as a mechanic, an inspection would be a good idea). A cracked/warped block (from running without coolant or oil) will blow smoke or leak, but a charlatan who is committed to deceiving you usually can for a short period of time, so I try to feel comfortable with my counterparty.
It has worked out pretty well.