Well...
Almost easier to buy external modules than mess with the expansions. Depending on what model you have also. I've got 2 expansion cards, but when I brought the sounds up using the included floppies it wiped out some of my regular presets. Anyway, I was able to locate restoration files online, but that sh*t was real lame. I think the 'pro' Tritons and the newer extreme models handle internal ROM a bit better. Not sure, I own a 61-key classic orig.
So..I think the answer to your question would depend at least partially on what model you have. I would also look into some of them Emu joints though, Planet Earth, MoPhatt, Virtuoso, etc...$200 or less is def. a good deal..lots of sounds in those synth modules. Also, a Roland 5050 with some expansion cards would be pretty cool too.
