Try asking here
http://www.bautforum.com/forumdisplay.php?f=52 but tell them your requirements.... a 16 inch dob. isn't going to do you any good if it just sits in your closet except for rare camping trips and a cheap little Wally-world refractor may wind up just being an irritant that you'll throw in the closet and forget. You want the best quality you can get for the money and as much size as you can get, but it has to be small enough and portable enough that you will actually use it, otherwise it will just gather dust.