Too expensive for what it is, they're probably ten a penny in Oz and you could import one yourself and sort out SVA loads cheaper.
Now, if you can find me a 2000 (or even 1999) 850CSi for £17k you can have my MV6 as a finder's fee! Crashed or otherwise damaged doesn't count
Seen a few 850Ci ones on autotrader, I take it there is a big difference in the CSi ?
Yes. The 850CSi is basically the M8 but was never badged as such as they planned to release an absolute beast as the M8. A prototype was build but it was never finalised as the market for megabucks cars crashed. So the CSi was actually built by BMW M Gmbh and has the initial characters of the VIN that all M cars have. It has "Powered by M" on the engine cover too. 380 BHP, 6-speed manual gearbox, sports seats and suspension, active rear kinematics (standard I think but don't quote me) and adaptive damping. Also had a quicker steering box, M-tech aerodynamic mirrors, upgraded brakes (floating discs up front, 345mm discs) and the M-Turbine II directional 2-piece alloys.
Lots of really subtle differences, and they're pretty rare (although funnily enough not as rare as my 6-speed 840Ci lol). Very sought after, which means you'll be lucky to get a good one for £25k and even then it won't be one of the later models, production ended in 1999 I think.
The 850Ci is still a good car, but nowhere near the 850CSi. They are much softer, many are slushomatics, engine is less tuned (306-320 BHP). Even the later version with slightly more power is actually no faster than the 840Ci due to the extra weight of the V12, and the 840 handles slightly better too due to the lighter engine. Hence 840s tend to be worth more on the used market, as they're also cheaper to maintain.
If you want even more exclusive, look to the Alpina B12 5.7 Coupe. Based on the 850CSi it's been tuned to 420 BHP with the same 6-speed box. Only 17 were produced, and a good one will still fetch £50k if you can find one