As most of you know, a whole bunch of D&D PDFs have been uploaded to RPGNow. And I was torn between wanting to pick up certain items due to nostalgia, more items due to the collector instinct, and other items due to curiosity.
Here are the items of interest for me (so far), and why they stood out from the others:
I never owned this module. My copy of Basic D&D (with the classic Erol Otus cover), came with B2. Because I didn't understand how these RPG thingies worked, not having B1 troubled my young brain.
According to the product page: "An Introduction Inclusion. B1 was immediately packaged as part of the Basic Set - replacing geomorphs and monsters & treasure assortments, which had required GMs to be more comfortable creating dungeons on their own. It appeared as a part of the Holmes Basic Set from late 1978 through the end of 1979, at which time is was replaced by the better-known "B2: The Keep on the Borderlands" (1980)."
Hell, my first module purchase was T1 -- The Village of Hommlet because I figured it was the first in a series of games that needed to be played in sequence. It was only later that I realized that the rules I had didn't match my Basic & Expert Sets and that started me looking out for the Advanced D&D rules.
So, the reason for picking this up is all three: nostalgia, collector's instinct, and curiosity.
There's a fouth reason. In my mind, the entire B-series is set in Mystara, so I want to see how this would be integrated into that setting, given my more developed understanding of games, setting, and sandboxes.