I edited my comments to add the links to Twisted Throttle where I ordered the tankring.
For a cheaper tankring bag, check out Givi and Cortech. But be sure to choose a tankring that fits:
- 7-bolt Yamaha (e.g. 2003-06 XJR 1300)
- 7/8 bolt Suzuki (e.g. 2001-07 DL1000)
I chose the SW-Motech bag for my Vstrom because I liked the fit and volume, but I did choke a little on the price.