[ferros]

SR-60 and 80 are essentially the same with different cushions, you can read on this in, no doubt, countless topics on head-fi. In my personal opinion, Bowls that are supplied with 80s sound a bit better, but flats (with 60s) are more comfortable. SR125 are better, but I don't think that they're worth the extra money over 60s. If anything I'd go straight to 325, which are vastly superior but nowhere near your price range as well. As for Alessandro, it has different sound signature than pure Grados, so it is a matter of preference. I'd recommend choosing between SR-60i/80i or MS-1i after listening to both or at least reading some of the reviews.

*Update* After looking at Grado website I'm no longer sure if 80i ships with Bowls like old 80s did. If it is the case, the battle between SR60i and SR80i is easily won by the former.