I've tested over 200 mics for lute and one of the best budget mics is the Studio Projects B1. It costs about $90. It is cardioid, so it won't give you that omni sound.
And it is not a Schoeps M2 or a Sennheiser MKH20. dt To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
