new chips can be from £30 up to £150ish
The best, are Ultimap as they can be programmed with new maps for your bike
http://www.fuelinmoto.com.au/ If it's just open pipes, and your switching back to standard ones, use the original chip if you don't want to buy another.
I'd guess that a good dyno run would let you know if the chip worked or not.
For what it's worth, I run an Ultimap on my 748 that's setup for open pipes, different filters etc and have switched back to standard pipes when needed without changing anything - a little change in the power characteristics, but no misfires etc