As I understand the design of this type of telescope, there are several reasons for its low cost. First, the mounting is very primitive and not intended for anything more than brute force jostling of the tube to a spot in the sky. This reduces the cost of the telescope by probably something like 30 percent right from the start. The second factor is that the mirror is made of low quality plate glass or pyrex or some similar material, not optical quality Cervit. The mirror is about 1/2 the thickness of a standard mirror, and the telescope must be thermally equilibrated for at least an hour for the mirror to physically stabilize after thermal contraction. The mirror mounting is also very simple. This results in probably a second factor of 1/3 cost reduction, so that the final cost of, say, a Dobsonian 8-inch is in the range of $ 250-300 while a standard 8-inch might cost you $ 800 or more especially now that everyone seems to like Schmidt-Cassegrain telescopes.