valves off e bay worth it

Has anybody use the valves from nichie cycle off ebay for the. Z1 900 I bought all four for under $100

I bought all four valves for my 750 twin off ebay, they were good. I think the seller was Rusty Riders LLC?

Carefull.
Some of those cheap valves need work to fit.
They sit too high as the stems are too long and close up the valve clearance to zero.
Had some recently that needed 1.5mm trimming off the stem to get clearance and they still had over the 4.2 minimum above the collet groove.
You get what you pay for

I would assume any new valve would need to be fitted, since I can't get shims for my engine and the machinist worked the valves so the finished height matched original.

"oinkjohnson" ebayr sells stock valves all the time.
Your going to have to have someone quick gring them at a 45' angle
and get lucky and lap them in to the seats.
No easy fix, ya got to do it right