Mine lasted a good few years; FWMSWM; is the original no longer available (only a new formulation)? Last time I was at Gatwick or Heathrow someone was pushing out sprays, but I was not sure if it was the original formula; the bottle looked quite similar to the original, price as you stated.
I think that I probably know the answer already; why oh why do companies mess around with their classics. Yves Saint Laurent "Y" was my all time favourite women's perfume (and my partner's); again an all time timeless classic, used to be in a white box; purchased a few boxes when the final ones were being sold off (made some great presents for a few years). Again, no longer produced and nothing has ever reproduced that classic sophisticated aroma.
Perhaps these old classic are just not bling enough for the modern markets?