The RS is a pretty robust beast and there are plenty around with far higher mileages than that.
There's no issue getting service/maintenance parts - but third party extras like hard case panniers, bar extensions, bigger screens, etc can be difficult/impossible to get hold of now so if your going to get one make sure it has the extra's you want.
All the things Bluenight911 mentions in is first post are what I'd call service items that are available and don't cost much to sort if they haven't been done yet. Also they need doing when they need doing e.g. I'd not done my throttle body hoses or exhaust gaskets on my 2011 as they were still fine but I had done the HT leads when I changed the spark plugs for the first time.
If its stock or has popular upgrades (e.g. the ones that are sold by vendors on this site) then no issues, but if it has weird things like non standard wheels, badly made seat or a respray that would be a danger signs for me.
If it has a service history then I'd expect services ever 7500km (4600 miles), though personally I did mine at 5000kms (3100 miles). If you get the VIN from the right hand side of the swinging arm a dealer should be able to give you the service/repair history. This plate will also have manufacture date/version so you can confirm the year.
2008-2012 were the first generation RS's and the 2012 was the last of those so had all the minor niggles sorted. I think there was only one recall to replace the fuel cap.
They are a very rev happy engine and as a result the idle can be slightly lumpy, racing cam like sound.
Common issues:
- Cracked struts on the rear fender, most owners here get them repaired and strengthened rather than replacing them
- Brake warning will come up if the brake fluid is even a teaspoon below full, fixed by it topping up

- Fuel smell after riding - gas cap recall fixed this for some but also caused by fuel getting into the vapor canister - there is a fix for that well documented on this site
I can't comment on price because in New Zealand things don't depreciate like they do in the US.