thanks Graham! you are probably the alternative "playmodb"
No, all that information (apart from current availability of sets) came from Playmodb. It's not as dead as some may think; see
http://www.playmofriends.com/forum/index.php?topic=12802.0. One useful feature (which Heather admits only works because of "sloppy coding") is to enter
any part number in the URL line
http://playmodb.org/cgi-bin/klicky.pl?partnum=30%20nn%20nnnn (replace nn and nnnn with your part number) and you will get a list of sets containing that part.
I can't help with the question about how many parts you will get if you order 30 26 3130 from DS. It drives me crazy when you want, say 4 of a part, order 4 and get 16! That would be another useful piece of information for Geobra to supply to the fan community, along with comprehensive lists of part numbers!