i work in the 30k - 100k range without problems, calculations on my core 2 quad 2Ghz range from 5  to 30 min, this outfit is 98k and is the longer to calculate so far (i have some more complex in work), around half  an hour mostly because the sleeves are colliding a lot with Aiko3 and the outfit.

I create my outfits with Marvelous Designer 2, i never need to run drape frames since the cloth never intersect with the figure, and it's easy to change the density of the polys.