I was pleasantly surprised by the results of using the internals on my Tascam DR-2D.
It's a little weak on the base end of things, but otherwise handled a loud outdoor rock show rather well.
Samples can be found on this page
http://www.tylisaari.com/misc/shows/master.htm(and that was from inside a coat pocket)
It also has the advantage of being able to do dual recording.
Battery life isn't the greatest, but with the firmware upgrade, and a fresh set of rechargeables, you can get 5 hours or more without worry.
Yeah, it's not ideal. But it gets you started.
From there, you can pair it up with whatever mics, battery box, or preamp you want when you have the cash.