Is it possible to find a good DAC for under $50, 000?

Late to the party here. JMHO-A $50K DAC would most likely be surrounded with similar priced electronics, cables, speakers and a room with treatments. Therefor it is very likely that the sound quality would be more easily distinguished. So for that person it will be likely worth it to them. 

Late to the party fthompson251, but that's a very important point. I made the assumption that the rest of the system would be highly resolving, but it's certainly possible with a system of less resolving components even an audiophile with developed hearing could miss the value of adding a 50K DAC. Great point! 

No, I don't think you could get a good stereo dac for much under $50k. But you might be able to talk Esoteric in to selling you just one of their monoblock dacs so you could have decent mono sound for well under $50k. They sell the stereo pair for $55k.

https://www.esoteric.jp/en/product/d1x_se/top

Still a Benchmark fan here.  John Siau can back up the stats with science, and there's no BS in their marketing...and made in the USA. 

You wouldn't hear a difference between a $50k DAC and something out of $1000 AVR. Fact.