[mst]

I would not go for an old version, it simply is not cheap enough.

Well, that of course depends on one's available budget or use case (meaning how much one is willing to spend for a lens he or she might not need that often).

To add some numbers: the G2 locally sells for around 1600 and, since announced just recently, is only available new. The earlier model can be bought used (by those who don't mind buying used) for less than 800, so half the price.

-- Markus