Hey dfm3,
I have a pair of M 160 and really like them. The M 160 is a very useful mic for a lot of applications. I like it for drum overheads (great tom sound!) and electric guitar cabs, then often together with coincidenced condenser mic, or a M500, ... or just as. You need a good, quiet preamp if you want to use it on quieter instruments. I bought them used and never had problems with them because Beyerdynamic has a great support for their products. So don't worry about ribbon wear, they can be replaced.
I had one of them re-ribboned about two years ago and it costed me less than 50 Euro (about 60 $), if my memory serves me right. I needed a new transformer on one of my M 260s and that wasn't a problem, either, just a bit more expensive. The shipping wasn't an issue because I lived in Germany, back then. Shipping to the US or Canada can be expensive (about 70$, to Germany and return).
Two or three years back you could get Beyer ribbons real cheap on German ebay,
www.ebay.de , but then a run for ribbon mics began and most Beyers went to American buyers. I think you shouldn't pay more than 200 $ for a used M 160.
It's the same old story about the boys from the south went up north to dig the Klondike and fish our grounds. I feel a bit homesick as I'm typing this.