For sale is a left side BMW system case that I've used on a 1996 BMW R1100GS -- it's got the cutout to fit over the exhaust.
The case is in overall good condition, but it IS from a GS, so a little scruffy here and there. The shell is very good.
The case is lockable and includes a single key. You can get it re-keyed at a BMW dealership.
I 'think' this might fit other bikes, like a R1100R, but don't know this for certain.
If you've just picked up a used R1100GS, you can use this case on the left side and your RS or RT case on the right side.
Price is $100, plus shipping costs.