How good is 8000 dollar Sony Dac transport from 89

There is no comparison. It's like comparing my 1987 20MHZ computer with a 20Mb Hard Drive and 640 KB RAM to my 1.7 GHZ computer today. Digital technology improves exponentially. Buy someting made in the last few years with at least 20bit DACs for the best results.

agree with Buckingham on the dac front, however, I bought an older reference transport, Teac Esoteric P1 ($6k USD in 1988), and it is excelllent! Detail retrieval, air. cymbals have nice shimmer, etc. I have a half decent dac and cabling, so that helps, but don't be afraid to pick up a good older used transport, and pair it with a newer dac- you might be surprised!

We've talked before, if the price is right, go for it. I'll bet it still sounds great.

I'd expect the DAC to be dated, but one thing about the early Sony top of the line was that there apparently was an excellent interface between the units that was way ahead of its time (sort of an I2S, I think). Might not sound too bad for the right price; certainly a collector's item.