B & O 5000 cartridge source?
 

http://www.sound-smith.com/cartridge...o.html#classic

They have the most reasonable price for any B&O compatible cartridges
of pretty much anyone. B&O has long since stopped supporting the
turntables with new manufactured parts.

Double check the cartridge number, but the compatible MMC20e is a
reasonable $229 plus S&H from them.