Some nice recordings of old-time tunes on clawhammer banjo and various other instruments.

Huge collections of digitized old-time and early Bluegrass 78 RPM records available for purchase on CD-ROM and DVD-ROM. Dig around and you'll find some generous free samples.

So after a few days of eying my fiddle from across the room, tentatively picking it up, making a few notes and putting it back down, I decided to try playing a couple of tunes by ear - ones that I've been playing on banjo and/or mandolin for at least a few years, and know like the back of my hand: Soldier's Joy and Angeline the Baker

Well, duh... the simplest possible melodies of both of those tunes just fall right off the fingerboard, and can be played with just the sort of back-and-forth bowing you'd expect.

I sounded like hell, but being so familiar with the tunes, I didn't have to search very much for the right notes... and even with my squeaky, off kilter playing, those simple quarter-note melodies sounded better than they ever do on Mandolin, which has no sustain to speak of.

Knowing a bunch of fiddle tunes before taking up the fiddle is probably going to be a big help.

http://www.fiddlerwoman.com/id99.htm

The general theme I am sensing (and my own experience is no exception) is that you are in for a no-frills experience if you decide to buy one of these instruments.  You should have no illusions that you are getting something that will be ready to play out-of-the-box, and as Beverley Conrad states in her post, you may wind up paying a lot more in setup and accessories (new bow, shoulder rest, etc.) than you might have anticipated.

I'm optimistic, though; I'm fully aware of the potential shortcomings of my cheapo devil's box, and I've played enough music on enough different instruments that I think I'll be able to tell if the wall I hit is due to being a newbie, or to having an unplayable instrument.

"So many people get into problems and give up when they try to teach themselves to play the fiddle - so, I wondered, would a few words of advice help some to enjoy playing the fiddle and fewer would give up in disgust?"