A 4.5" reflector is a small scope. They run about $200 brand new. The best advise I can give you is take iy out and try it out. Your not making that big an investment and that size reflector is about the smallest they make. Check that the mount is stable, but remember they're not all extramly stable brand new right out of the box. Check for obvious scratches on the mirror. Check if it's collimated by pointing at a bright star and defocusing it. You should see a donut shape. If the center of the donut is off center it's out of collimation. There should be screw at the bottom to turn to adjust it. If you can't colimate it, don't take it. If it's OK, it should ber allright. Also check all the moving parts that nothing is loose. Make sure the eyepieces stay in the holder tight. Good Luck;
That's it;
BOB SAL