I have two minidisc recorders that can be used to tape concerts. I haven't yet decided exactly what I will be offering along with the recorders, but it will probably include a power supply for charging batteries, one battery, and some blank discs to get you started. Depending on what I offer along with the minidiscs, I will probably ask for something between $25 and $35 plus shipping for each recorder.
The first unit is a Sony MZ-R91. It's in pretty good condition. I have used it to record over 50 performances, and it has only given me problems once (at a very crowded hot show with a lot of shoving, it stopped recording without me knowing -- either I accidentally forgot to put hold on and bumped the off button, or maybe there was a problem with the battery, or maybe it shut off for some other unknown reason). This minidisc has a microphone jack so you can record with any microphone you'd like (though recordings of concerts turn out much better if you spend a couple hundred dollars to get a microphone with a battery box, designed for high sound pressure situations).
The second unit is a Sony MZ-S1. It's not in quite so good condition and has had a few more problems (Matt and Nikki borrowed this from me, and they both had to hit it a couple times in order to get it to turn on sometimes, but I've never had to do that myself). This one has shut off while I was recording twice, but I think it might be because I was using a rechargeable battery that doesn't seem to hold a charge very well anymore. This unit has a line-in only, no microphone input which means to record with it you MUST be using a microphone with its own battery box to supply power to the microphones (which isn't that much of a problem since that kind of microphone sounds a million times better than microphones that aren't powered by their own battery boxes). This minidisc has the nice feature of having a back-lit screen, so you can easily see what's happening as you press buttons in a dark venue.
I would really recommend the first one, the MZ-R91, to anyone who wants to start recording shows but doesn't want to spend a lot of money.
Also as an added bonus, I will be keeping my full-sized minidisc deck that I use to transfer recordings to CD without losing any quality (portable minidisc recorders have no way of doing this without losing a lot of quality). So if someone buys either of these, I'll offer to transfer anything they record to CD for free, all you have to do is mail me the minidiscs and then I'll mail them back to you along with either a copy on an audio CD or a copy on a data CD or DVD in the FLAC format (which is very commonly used online for sharing and trading live music on the Internet).