I'll pass on the advice that I've found to be invaluable over the years - from a photographer I respect a *bunch*:

"Before you buy anything, ask yourself one question: What am I going to do with this new *whiz-bang" device that I could not do with my old ... fill in the blank...?"

Too many of us ... at the time I was one of them ... buy equipmant we do not need for the "prestige" factor: "Gee, he has a Leica - he must be good". My friend advised me, "If that is what you are out for, get a gold amulet and hang it around your neck. The prestige factor will be about the same, and it will depreciate *much* less."

An "Extra-Sharp" -- excruciatingly sharp -- lens is an example. Probably of extreme importance in copy work, and a definte disadvantage in portraiture... witness the "Softars".

What do you intend to do in the near to intermediate future? - Let that be your guide.