Pure Phono Preamp

By "gain control", do you mean a volume control, or the ability to adjust the set gain (and loading) via dip switches, resisters or even a remote control?

If the later, the ASR Basis Exclusive is a world class phono preamp, (read all the glowing reviews in Stereophile, Absolute Sounds, etc.). It allows you adjust the set gain (and loading) via DIP switches. This preamp works great for very low output MC cartrdidges (my friend uses a 0.2mv output cartridge), or MM cartridges. One reason it works great, and is so quiet, is that it is battery powered, (and it automatically recharges the batteries when not in use). Used they run for just under $4K. (And as a bonus feature, there are actually two phono preamps in the unit, so you can run two tonearms.)

My two cents worth anyway.
Good Luck in your search.

My two cents worth.

Kurt,
Not volume control. Gain for different output carts. Using it to plug directly into a Prism A to D for accurate transcription. Not a part of a home setup. Could be just a phono stage if it has balanced line out. Need clean, accurate and simple.

Here are three that meet what your looking for. I have owned all three and personally prefer the Sim combo, but all sound very good, are flexible, and are solidly built from respected companies.
Simaudio LP5.3 with PSX5.3 power supply 2750.00 new.
Ayre P-5XE was 2650.00 when I bought mine new.
BAT VK-P10se they come up used for around your max price.