If you buy a TD-30 you will get the TD-20X also! The 100 drumkits of the TD-20X are hidden in the Setup menu of the TD-30 (press Setup - F5 - F1)
For some reason this information can not be found in the manual...
So you get 80 TD-30 kits and 100 TD-20X kits. The latter can not be edited,...