Unfortunately, as you go up the model line, the better the sound reproduction.
I have owned almost all the Schiit line. From Modi to Gungnir.
The Bifrost Multibit is probably the best buy, but at $450 used, a little over your budget.
The Modi Multibit is certainly in your budget, and I think you will be happy with it.
The thing about DAC's is that they are moving at a fast pace regarding sound quality reproduction, so I try to find a manufacturer who will offer upgrades.
Both Ayre and Schiit do so, and are the ones I buy.
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