I am into collecting slightly obsolete audio gear, I've spent maybe $600 on the hobby in the last six months.
I know some people would think $120 is a lot for a minidisc player since you can get a flash player for so much less. Other people would think it's a trivial amount of money. Like all these things it comes in multiple scales: back in the day there were people who would spend 50x that on audio gear (there are some $20,000 speaker sets that sound great)
I don't expect to impress anybody: the last person I showed my portable minidisc player was a professor in the music department who's won one more than one Grammy award and teaches sound engineering who I ran into at the bus stop and his comment is "God, how can you listen to something compressed like that?" ("... yeah, I've been wondering about some of the coding tools they use.")
We are probably going to have some people over for a party and I don't expect many people to notice the difference with the 5.1 DTS discs I have in my CD changer but I do.