$250 sounds kinda steep for a used P22, at least in my area.
But if the price sounds reasonable for california, then i'd go ahead and buy it. If its a lemon S&W/WaltherUSA has excellent customer service, and they'll make it right.
Take a look at the posts under the Walther Rimfire section.
even though my P22 has the latest "A" magazines, I've had my share of issues with it. Do I still like it? Yes.
I do need to check the firing pin spring tonight, due to those light strikes. Some owners have had no problems after break-in. Just depends on the particular P22.
Regarding NIB price, local here in MA: