Advice Please

I would recommend either Minolta's big beercan (http://www.dyxum.com/lenses/Minolta-AF-75-300-F4.5-5.6_lens52.html) or Tamron's 70-300 SP DI USD (http://www.dyxum.com/lenses/Tamron-SP-70-300mm-f/4-5.6-Di--USD_lens595.html, none of there less expensive 70-300mm tamron lenses).

Minolta made many different lenses with that focal length, the original big beercan version is likely the best of them, but also the largest and heaviest. Several of Minolta's newer 75-300mm lenses are very good also, the Sony is very likely originally the last of the Minolta designs.

I don't do much with macro lenses, but have the Minolta 50mm f2.8 and am very pleased with it. There's also a Minolta 50mm f3.5 that's likely less expensive. I really don't know how the focal ranges compare or anything about the quality of the Sony 30mm.