There is no reason why phono preamps need to cost a lot of money. They are electronically simple, with simple methods of applying the RIAA equalization. Of course, that doesn't stop some companies from charging vast sums on what is basically a simple circuit. The laws of diminishing returns is reached quite rapidly with such a basic circuit. The chassis is likely to cost more than the circuit inside, especially if 3/8" thick billet faceplates are involved.

Almost any reasonably good IC, transistor or tube circuit will provide bandwidth, distortion, and noise performance which is better than the vinyl it's self. Vinyl is limited in the bass region by the practical excursion of the grooves, the compliance of the stylus, and above all, low frequency noise from the mechanical nature of the reproduction method. The high end is pretty well signed off by 15kHz due to practical limitations on detail which can be cut into mechanical grooves, especially on the inner bands of an LP.

It's a miracle that vinyl can sound so great, given the hurdles it has to overcome, but the fact is that it does it very well. Better than most commercial digital recordings from my experience.