I havent seen the MASH set at all recently. I've been checking, but maybe I'm looking in the wrong places.
Supposedly, there is a new kit, being offered by another company thats been said to replace MASH. (read the reviews, people are insanely happy)
This kit is $11.99 for 25 plates
I'd suggest checking into it if you love nail stamping. The plates are numbered like the Konad plates.