Sorry I've been on a thread-making tear lately...

I'm in the market for a new bike. I'm a purist and prefer my bikes to be pretty much stock, but unfortunately for me the sprocket mod is very common. How much money should I expect to spend on returning it to stock? And please enlighten me on speedohealers. Do I just take it off once I put on stock sprockets?

Also, how much top end do you lose when you go say one down in front, +2 in the rear? Not that I'm likely to ever go that fast or should, but still curious