SpooferJahk: You are not alone, I adore Blood as well. I probably would not have ever played it if it wasn't for the abandonware sites I visited back in 2004-2007 and I thank those sites for exposing me to a lot of different DOS shooters I missed out on that are underrated like Strife, Nitemare 3D, and of course Blood. I like Blood enough that I am trying to track down physical copies of the game and its expansions.
Roman5: good luck...some of the hard copies and expansions are incredibly expensive...
... But not nearly as expensive as it was before GOG started selling it. If you can settle for a used disc in good condition, Blood 1.01 (no PP or CP) can be found for under $5, OUWB (what you get from GOG) can be found for $30.
Check Amazon and Half.com