You can find used airsoft snipers for sale at websites like Amazon or even good old eBay.com as well. But if you want brand new, name brand airsoft snipers for sale on the internet, then airsoftsniped.com is a pretty good website for that. However, you may find that Amazon has cheaper prices, especially if you choose to go with used airsoft sniper rifle. But then again, if you buy used, be careful, and buy only from a trusted seller with good feedback of course.
You can also find airsoft snipers for sale on a few other good websites, like airsplat and pyramydair, just to name a couple. None of those sites sell used airsoft snipers, except in special cases. But they do have some really good prices on the brand new airsoft guns, and they carry all types of airsoft rifles too, such as airsoft pistols, airsoft shotguns, and much more. They are probably worth checking out.