i guess that buying "unknown" cheap scanner has lack of quality, seems that something like canon, hp, etc... has good quality in even lower price scanners =) and of course most expensive one is not most best, there is good scanners in cheap/low price category too (like Grimtwist seems to have)

Flatbed scanner is best for photos and for most of things, i bought new scanner to myself (Canon N1240U) and it is my fourth scanner and best i ever have had. there is differences between scanners (image quality) and i have not so good experiences about most cheapest scanners.