Digital cable...

I'm using a Grover Huffman AES/EBU cable from my CEC TL-2 and (2) Grover Huffman coax cables, one from my Olive 04HD music server and one from my Squeezebox Duet to my EE MiniMax DAC and LOVE them! They sell new direct from Grover for around $100 or so. They have a 60 day trial period. If you do try them, they require at least 200 hours to break-in. I would recommend even more.

The Kimber Illuminati is also an excellent choice. You could also try the Black Cat digital cable. The same designer of the Illuminati.

I like the Oyaide DB-510(bnc) or DR-510 (rca). They take a while to break in and can sound strange for a couple of weeks. After having used many digital cables over the years this my favorite.
Remember, if you buy one, no serious listening for a couple weeks.
This cable is in your range new but you may be able to find one used for even less.

Cardas Audio's Neutral Reference Digital since you already like the Cardas brand.
314.00 new , so used would fit in your price range. Plus. the cable would already be broken-in.

The price I quoted for a new Cardas Audio's Neutral Reference Digital $314.00 is for a 1 meter pair. $236.00 for .5 meter.

Check out the Blackcat Silverstar 75

$150 and has a good story.