I looked at phono pre amps and found a wide range of prices. From 25.00 to 2,000.

I'm scratching my head thinking they can only make it sound so good.

Hagerman Bugle http://www.hagtech.com/bugle.html got decent reviews.

WHy would someone spend more on a phono preamp than the cost of an entire amp that comes with one?

The limiting factor is the record itself.