Yep -
Beyerdynamic makes several models (M130,M160,M260) that you should be able to find discounted to under $500. Sorry, I can't tell you about sources, I bought mine from a former Beyer rep.
The RCA SK46 comes to mind...can sound very Royeristic (some of them do suck, though)...and can be had for under 200 bucks...
Broken ribbons can be a bargain...I always believe in rebuilding ribbons anyway, so why not buy a busted one and have it re-ribboned for 125.00-150.00? A basically new mic is the end result....
The BK5 at 4-500.00 is one bargain in the ribbon mic world, IMHO. An incredible mic on guitar cabs, horns, and even vox...
But the BK11 is the all-time hands down winner in the bargain ribbon mic catagory. They are about my favorite mic, period (even over a 77DX or 44BX), and can be had for 800 bucks. Compare that to the 1200.00-1700.00 that the 77's and 44's go for...and I'd take one over a Royer anyday...