I have had a QL-F4 for quite a while, and paid $20.00 for it with a great cart.
I happened to have gotten very lucky.
Your QL-Y3 is a step or 2 above my F4.
Sonically, my F4 surprised the krap out of me, it was really musical.
Recently got my hands on a QL-Y66F in challenged cosmetic condition, but perfect operational condition. I can tell you now, this is a keeper. Paid a bit more for this one.
Point is, you will pay what is appropriate considering condition, sonics and pedigree.
The JVC QL units are under the radar right now, and I see no reaqson why a Y3 should not sell for up to $300.00 in great condition.
Just my 2 cents . . .
Cheers