My two favorite cheapies are the Creek OBH-8SE (not the regular OBH-8, which is not very accomplished) and the Musical Fidelity X-LP. Either would cost under $150.00 used. A big step up would be the Musical Surroundings Phonomena at around $225.00 or Phonomena ll at $350.00 or so. Another choice in your price range is the Graham Slee Gram Amp V which will top out your budget.
You did not say what cartridge you are using, but the Creek and Gram are only designed for MM cartridges; the others will work with MM or MC cartridges.
You did not say what cartridge you are using, but the Creek and Gram are only designed for MM cartridges; the others will work with MM or MC cartridges.