Dac Suggestions around $500

Hello Everyone! I need some advice about what dacs I should be looking at in the price range around $500.  New or used is fine.  I’d like it to be able to decode hi res files since more and more of the music I stream off Amazon HD seems to be in high resolution.  

I’m going to using my bluesound node 2i as the source which leads me yo another question; is digital coax going to output hi res or do I need to go usb?

Thank You ahead of time!  
IMHO, if you're looking for a DAC around $500 then maybe better to stick with the one in the node. You're not going to get a noticeable improvement in that price range. 
Just added a Gungnir Multibit, bought used, to my Node2. In video game parlance it's like I leveled up...twice. The digital coax puts out hi-res as far as I can tell. 
For around $500, you can get a used Benchmark DAC1, possibly even a later version. I saw one this week on Craig****t for $200. That's a good price for a great DAC.
Since you are looking for a DAC to serve while saving for an upgrade I would buy used. Otherwise maybe continue to use use the Node as is. Interest rates are low now, probably could pay off a loan at less loss than buying one DAC and selling it to buy another.