My personal two favorite mods affecting comfort:
1. Corbin
2. Floorboards
The Corbin was $324 shipped (I chose not to go the Corbin pillion pad route) at the time I bought it. Keep in mind studs, piping/leather color, and textured leather options are at no extra charge. I've read several posts where stock seat modifications done by someone other than the owner costs much more.
Just my 2 Zloty .....
Regards,
Tom