The market for target rifles is smaller than general hunting/sporter rifles, Personally I would only buy from a forum and normally from people I can trust or others will vouch for, (Feedback etc) Target shooting is generally quite costly, getting what you expect is paramount to any purchase and buying from a known source is the best way to have confidence in handing over large sums of cash, It also depends on what the rifle is, the market your selling to (starter/experienced etc) and the price/condition,
There are people on here I would happily purchase from, trust fully and in many cases would be happy to buy on description and good repute alone then excitedly await the post van, I can't say the same for general sale sites where I would absolutely want to view and test before handing over any amount of cash, So if it wasn't local I wouldn't bother and that again limits your market audience.