First off- Congratulations on your new Audio Research gear! I use ARC as well and I’m sure it will bring you many years of enjoyment. In reading your post regarding interconnects I don’t think you mentioned what brands you’re currently using.
As for a gauge of how much you should spend I don’t believe you should be putting any pressure on yourself to align cable/IC costs with that which was spent on your equipment, the two don’t even compare with regards to manufacturing costs or even research/dev/IP.
I’m not an advocate of overpriced designer cables but I also don’t shame those who choose to spend their money on such. What I would offer is an easy way of determining the value for yourself.
Canare L-4E6S is one of the best audio cables made (Star Quad) and you can purchase an 8’ pair of balanced XLR I/C’s for under $100 from Blue Jeans Cable. I’ve used this for all of my balanced cable for years and have never felt like I was needing more. This is one of the most (if not the most) highly used cables in the audio industry.
The purpose of this is not necessarily to sway you into using Canare but to rather give you a starting point with an industry proven cable assembly that is the equivalent of what is used in most recording studio and live sound applications. Please purchase a pair to have on hand for comparison when you demo the multi thousand dollar I/C’s your dealer has suggested and also request your dealer make the cables available to you for a trial test in home on your own equipment.
Even if you like the higher dollar cables better at least you’ll have an accurate gauge for cost comparison. Do these really sound $1K better each or is the difference so subtle that it’s not really worth the money? Do they sound different at all? That’s the big question!
Also- don’t EVER allow yourself to feel like you’re system is subpar because it’s not not sporting the high level “bling” that some will say matters- it’s how it sounds that matters most.
Best-