Any good quality DAC in $300-400 price range?

I was in the exact same position as you a couple months ago. I bought this:
http://www.ebay.com/itm/Valab-WM8741-24bit-192k-USB-DAC-Dual-WM8741-Balanced-XLR-Output-Black-Face-/300703596949?pt=US_Home_Audio_Amplifiers_Preamps&hash=item460354c195
Dual mono, excellent build and parts choice. Inputs all formats and plays all frequencies. I am very happy... Note, USB is the tenor 7022L, usb only does up to 24/96 and is not Asynchronous. I did add a USB to SPdif that was Asynchronous and had galvanic isolation...
In your pricepoint to get it all, the Schiit is an excellent choice and after having an upcoverting DAC, I have come to believe that playing native resolution is better.
The entry W4S looks great and the Peachtree iDAC has great reviews.

Sorry the Peachtree is called DACit

Thank you all for your great answers.
After reviewing everyone's answer and doing additional research, I've found that there are not many USB 2.0 DACs that support all of the available sampling rates. However, I think I'll have more options to choose if I get an S/PDIF connection. So I was searching for an affordable PCI sound card that supports various sampling rates and found ESI Maya44. Has anyone used ESI Maya44 sound card for S/PDIF connection? What's the major difference between USB to S/PDIF converter and PCI sound card with S/PDIF connector?

if you want an inexpensive dac that does everything... won't work on mac... Musiland Monitor 02US, Musiland Monitor 02 Dragon, Musiland Monitor 03US... they need some real break in, but surprisingly nice sounding.

Thanks Timlub for the Musiland DACs info. Yes, I've heard about the Chinese brand and good quality of their products. It seems to be pretty popular in Korea too. (I've read the article on a Korean website.) Since I'm a PC user (for audio stuff) who uses Foobar2000 for FLAC files playback, I should definitely try it!