What's a 30-year old Grace F9-E Ruby worth?

Since vinyl has caught on again, I brought out my turntable from the 90's and played a few vinyls. I was surprised to see that the cartridge still plays fine. To make a long story short, I not into vinyl as I once was. My interest has shifted to 24-bit music, limited as it is.

Any idea what this cartridge is worth given its age.