I bought a 1992 R1000 a few years back in similar condition and was happy to pay a bit over $500 for it. Top of the 1992 road line, same frame and fork but the (perhaps) more collectible Mavic 8 speed indexed build.
Beautiful bike with a very desirable build. I'd love to have it in the collection but it would be very hard to justify adding another vintage road bike that won't get ridden.
It will be interesting to see how this 1990 SR900 sells: