one point which may be a factor, though i don't know that myself (no personal experience, and too lazy to look it up in google...) is that wg and pt might be bad heat conductors compared to steel, and thus the watchcase would be warmer (and more pleasant) to the touch.

also, one has to keep in mind that a precious metal watchcase has an intrinsic value. i guess that figuring the market price of gold or platinum, there might be about 2000$-5000$ worth of material in a single watchcase. granted, the manufacturers waaaaaaay overcharge on the precious metal watches if one takes only the material value into account, but on the whole they're still not as outrageous as panerai with the pam180-pam104-comparison. maybe a surcharge of 100% for a gold case vs. the steel case is more the norm. still bad, though.

cheers, johannes