Where to Purchase New Tubes for Audio Research Preamp?

Hi all,

The tubes in my SP8 mk II were purchased eight years ago from Audio Research and are getting long in the tooth. I called ARC recently to order a new set and was told that the cost would be $500. This is almost twice what I paid in 2011. Anyway, I was wondering if there are other sources for tubes you would recommend that are cheaper? I found a store on ebay called Tubemeister which sells Genalex Gold Lion gold pin 12AX7/ECC83GP preamp tubes that it claims to be matched and balanced. Do you think this would this be a good option?

https://www.ebay.com/itm/AUDIO-RESEARCH-SP-8-MK-2-ULTIMO-II-Tube-Set-Genalex-Gold-Pin-Our-Best-Set/2...