"Someone needs to make a cheaper and possibly better XLR adapter [than Sony's $500 model]"
Assuming your mics need 48V phantom power, try the ART Phantom II (~$65) or the Rolls PB224 (~$85). Both use 9V cells to provide 48V phantom power via XLR connectors.
If you're using the D50 or another recorder that uses a 1/8-inch minijack for mic input, you'll need a cable like the Hosa CYX401F, a one foot long cable with right angle 1/8-inch stereo miniplug on one end, and two female XLR connectors on the other.
If one foot of cable is too short to connect the battery box to the recorder, use the CYX-402F (2 feet long) or CYX405F (5 feet long).
Flintstone