I'd steer clear of the absolute bargain basement lenses and look for a clean used 80 mm EL-Nikkor, Schneider Componon-S, or Rodenstock Rodagon. The 75 mm enlarging lenses are ok, but if you make large prints or do more than just a little cropping, the deficiencies of the 4 element design will start to show up. The lenses I mentioned above are a step up in quality and will serve you well for many years if well cared for. They are all equally good, so no worries about the brand. You should be able to find one for not more than your budget allows.