Jon, Melody Assistant both inports ABC and produces TAB. Apart from my comments above I believe that the cost is much less than $50 (maybe $29).

ABCMUS will act as a very convenient interface to allow you to import files to NoteWorthy at a cost of $10, plus the freeware I mentioned above.

I'm not a TAB user, but the shareware palaces such as ZD-Net used to have a reasonable selection.

Regards
John