Hi
I'd like to point out that the page on shopping in Prague misses a great shop.

Porcela PLUS, Na Prikope 17, 224 210 574, 224 239 653, shop-75@porcela.cz

This is an outlet store for Sklo Bohemia/ Bohemia Glass. I have found excellent deals, including:
Hand-blown 24% Pb wine glasses, uncut, $40/6 (at least 1/2 the price of comparable products available in the US, but this was on clearance)
My brother and his fiance's wedding crystal, cut crystal, 24% Pb, 12 wine glasses, 12 water glasses, 1 vase, 1 napkin holder, 2 candle holders all for about $250 (And I can get it tax free by filling out a single form, bringing the price down to about $220)

This is the place recommended by my Czech boyfriend's parents and is the only place where they would buy crystal because they say everything else is overpriced.

However, there should be a note of caution -- no one should buy crystal in Prague without doing some research into what is important in crystal. There are plenty of unscrupulouos dealers out there. You should know the difference between glass (no lead), lead glass (<24% Pb), and crystal (>=24% Pb). If it does not have a sticker on it saying it contains at least 24% Pb, it is not crystal. Moreover, the pieces should be inspected for bubbles, scratches, and chips. If they won't get you a new piece, don't buy it!