what is the best, least costly DAC...?

The advice to bring a $300 DAC to life with a $1700 digital cable is astonishing in its stupidity.

Breathtakingly stupid advice.

Check out the $300 HRT Musicstreamer II+. It does asynchronous USB, handles 24/96, and sounds incredible! Highly recommended. Not quite as good as my Bryston BCD-1 Cd player but close enough for my music server. Money well spent.

Kbarkamian - V-DAC is ANYTHING but dull and lifeless sounding. It is very transparent, with excellent resolution and soundstaging.

If you found it dull sounding, than it may be one of two things:
- your DAC was faulty
- your system was voiced around old Theta gear, which is known to be very bright and brittle sounding. I know Thetas very well, since I owned a dosen of their dacs: Cobalt, Prime II/IIa, Basic II/III/IIIa and Gen V/Va/Va balanced.

Here is an excelent review from hifi critic:

http://rapidshare.com/#!download|266|422349120|MF_V-DAC_HiFi_Critic.pdf|9181

and German AUDIO:

http://www.taurus-high-end.de/infomaterial/cambridgeaudio/test/test_dacmagic_audio0109.pdf

used Vinyl

For the most part the chips used in all DACs are insanely cheap, a company like MF that has a skilled engineering team and low manufacturing costs can leverage those to make an excellent dac that retails for very little money.