If I were you, and was considering a scope from a private source I would request to see the scope in action first. If you can. If you buy over the net you will be taking chances. The SCT has a little more maintenance than other scopes. Need to know if the mount is sturdy and the worm gears are "tight" no backlash. Is the motor drive (if any) in good working condition. The optics need to be checked for scratches, good mounting. Don't worry about alignment, you'll need to learn that anyway. What accessories will you recieve with it. Some people sell scopes without a thing because they bought a newer scope and will use what they got. You'll have to buy your own accessories. Many things to ponder before you buy used. Good Luck!!