The GB usually commands a higher price than the standard Mini. It is already a second owner rifle and has an unknown number of rounds through it. Check the crown, bore and chamber for wear. Shoot it if you can. The 181 series rifles were fairly accurate rifles for what they were intended for. Three to four inch groups, open sights @ 100 yards was about the norm. For a good GB, $550 to $650 without extras. Can't really tell the overall condition of that one with those photos. Most Mini owners don't have just one magazine. Ask if he has more mags and maybe a case to throw in with the deal and that would make the price about right. Just my 2c.