Rick!!! Haven't seen you here in a long time. Hope you're well.
It's funny--I was looking at gear on eBay the other night and came across an Emulator (EIII? EIV?) that was modestly priced. That or an Akai s3000...$400 or so. An Alesis QSR will also play back samples and is listed on Prepal at $273. That would be a great solution for just triggering a short part, and at 1u it's a small footprint. (I still have one, but I'm reluctant to part with it.)
I wouldn't recommend using an mp3 player for flying in a critically timed part. We've tried that with embarrassing results.
Or, you could try the Sven method. Might be cool enough.
Take care, and stay out of those nasty stores!!

Ken