Jools brings up an interesting point. Do you spend the two to three grand on a 2-valve engine and have it produce 100 hp or take the value of your bike and put that £2-3000 towards something newer and "better"?
Other than a 851-888, or possibly an old 70s Ducati I can't think of a bike I'd consider trading my SL in for. It wouldn't help of course that I'd only get a pittance for my somewhat battle-scarred version.
So p'raps including my bike I'd have an outlay of around £3500- max 4000. 100hp, enough torque to pull tree stumps as a part time career and good if slightly slow handling.
Hmmmmmm
Darren