wine glasses-size differences?

[curious]

I have been checking the archives, but didn't find much there, so am asking here.
How important are the different sizes of wine glasses, and how "fancy" do they have to be?
I bought a set of cheap ones (from Wally-world, in a hurry) and hubby has already broke one!

Do you need all those sizes, and if not, what sizes needs to be bought?
Does it have to be crystal? I know it has to be clear glass, and that the lip should turn up, that flutes are for Champagne, larger ones are for reds, smaller for whites, but do you need all that variety? What is a fair price to pay?
Help guys, I don't want to waste my money, I'd rather spend it on something else (good bottle of wine to drink out of those glasses, maybe).