If it is optically clean it's a very good deal. Turn the scope around and shine a light through it to look for imperfections inside and check for scratches. if it's clean it's a great deal
Own a STM65 for many years now and goto scope for hunting. Light and fits easily into a pack. IMHO not much of a difference between it and my ATS 80 HD which I use for scoring at matches. Check the condition of the lenses including removing the eyepiece.