Unfortunately, I purchased my MT-32 and SC-55 a long time ago (well, early 2000's)- and paid through the nose for them. My SC-55mkII I got for cheap though (90 bucks I think).
No offence caused, I was just saying, I don't have the money to do it
I don't watch eBay like a hawk so much anymore, for modules anyway. I mainly look for Sierra games, am very happy with my current music setup (well, I'd love an 5080 or Fantom, but obviously can't afford those).
50 is a good price. But over 120 for a SC-55 is in my mind a very bad price, and not something you can compare to and say 'a bargain'! (For example, I wouldn't consider 100-110 a bargain for a SC-55, even though it's not 150+). But yeah, 50 bucks is very good.
Best was when I sold my old SC-55 on Australian eBay, for 250 bucks (200 US).