Skywatcher and Saxon have Mak-Cat horribly cheap! (could be horribly made too??) Only up to 6" on this site though. Celestrons are at the top of the page, but someone wanting a cheapo Catadioptric can get the Maks further down the page.
Go here and click on 'Catadioptric'
http://www.andrewscom.com.au/site-section-10.htm