I guess harder to come by, but I always like to know what the current price for a new one is, that for me determines if I really want to part with it. For instance I'm selling a 2 tone Bersa for 240 but back in 2008 they sold new for that much now they sell for 300 ish now.
the only way i gauge current price is by being active in the current market
aka comparing prices from acorss the board (msrp is usually 1 hundred to 2 hundred bucks more on average i find)
and the bersa has always been a 275 to 300 dollar gun new for the most part
i mean, when did a used SW sigma go for 300+?

