And while your original example might not work straight across, plenty of people in these economic times would gladly trade you a 1200 for your 1150 plus some cash.
The trading works better say if you wanted to trade your GS for an RT, there are lots of guys who have an RT but have seen the light and want to get dirty. ;)
I'm sort of the other way around, I have a GS and although the wife loves it and won't let me do this, I don't ride it mush as intended and might be happier with an RT and a WR250 or something.
Sorry to ramble but you gotta get creative.