Its pretty rare now a days. I can't seem to find any of NIP's shit in the stores anymore except for the one I put out on Rest In Peace / Black Market Records.
Here's a pciture of one of the tape I found on Ebay:
NIPs stuff is pretty few and far between. I've never seen anything beside ROTP and IWAK in stores. Now all I see is ROTP. I only obtained 3 of his albums. I got "Now Watch 'Em Drop" off PT on my computer though. Favorite track I've heard from NIP.