The 998 V-Twin is a great engine. If ridden as designed, it will last a very long time.
The 2012 was the best V-Twin RT model made.
Most parts are still available for the older RT's. This is more true for the 2012 than the 10 or 11 models. We've only had issues with a few components on the 2010. Even then, we have been able to find what we needed.
There are some things that should be addressed on the V-Twin bikes. But they are inexpensive and not difficult to do yourself.
Dealerships tend not to want to work on the older Spyders. But if you can do normal maintenance yourself. You'll not only save money, but you'll probably get superior results.
You're not going to take much, if any, hit on devaluation with the older Spyders.
Handling on the older models is not up to the standards of the new machines, but this too can be mitigated quite a bit.
Depending on your needs and abilities, I think a 2012 RT could be just the ticket.