Response to an inquiry made directly to CarboTech:
The last time I looked (quite a while ago), Carbotech 1521s for my stock GT were over $300. If they are cheaper now, that would be good to know. But $50 for a set of Bendix police pads is hard to beat and considering the low miles I put on my GT (only 35K miles now), I can deal with the dust.
The CT1351-1521 retail for $208. We do offer club and forum discounts if you buy directly from us. We would have to make these, 2-3 days to have them ready to ship.
My listings show the same 4 pot Brembo, the CT1001 for both the CTS-V (2004 edition) and the GXP. If you're looking for the 1521 in that pad shape, they retail for $170 and are in stock.