Need integrated amp with built-in USB DAC

Purchase a Behringer UCA202 to add optical out via USB to the Mac. Then you can get a unit with a toslink optical connection. You'll have way more options going that route than restricting to ONLY units that have USB.

http://www.amazon.com/Behringer-UCA202-Audio-Interface/dp/B000KW2YEI

This may be perfect for you. Price is even a bit lower than your limit, but it is worth more.  It is still a pretty new model.  Its from the same people who gave us the high-end Nuforce products ... NuPrime IDA-8

There is an expired add in this forum.. Look here:   http://tinyurl.com/o8mhjcj
I want to get one myself.

Gene

Dared i30.Peachtree Audio.