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

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.

To hear a difference ask for synergy between gear pieces and a wise control of the acoustic parameters of the system/room...

Purchasing a costlier piece of gear solve nothing....The job begin after...

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

I certainly have been able to easily hear the difference between $1000, $2K, $5K, $8K, $12K, $17K and $22K DACs... I sure don't see why I wouldn't hear the difference in a $50K DAC.