Table Deck_Reg
Key - Deck_ID
Key - Card_ID
Key - MainDeck_TF (or some other indicator for maindeck vrs sideboard
Field - Card_Quantity
Sorry if someone already mentioned this, but I haven't finished reading the thread yet.
I think it would be better to have two quantity fields; one for maindeck and a second for sideboard.
I might be able to whip something up in perl for parsing morphling.de; it seems a lot better suited to this sort of task than any of the other languages mentioned and the DBI module means I can use the same database code for just about any database backend. I'm very pressed for time lately, so I can't make a commitment right now, but I want to see this project work