For just pipes, you don't need a dyno tune at all! The dealer just wants to pad his bottom line by selling you a dyno tune. They should have a canned map (which they will probably use anyway) that will accommodate a freer flowing exhaust.
Don't buy into the "it's a CVO" bull$hit! I currently have 3 CVOs and there isn't that difference that they are trying to play you with, if you are just going to install pipes.
If all that you are going to do is pipes, just get an add on "fueler" such as a V&H FuelPak or a FuelMoto micro tuner and you will be happy with the $$$ that you can spend on something else.
The '09 SERG had a V&H FuelPak and PowerDuals when I got it and that was all it needed, it ran fine. 'Am since going 113 and 'am going with PC-V / AutoTune and will be surprised if the '09 sees a dyno anytime soon.
If you plan to go any further past pipes (cams, pistons, heads, etc...) then you will need a dyno tune, everytime you change something, unless you go with something that has AutoTune capabilities.
Another device, The DynoJet PowerVision has much more expansion capabilities than the "fuelers" that I mentioned above, it 'flashes' the ecm and is not an add on like the "fuelers" and if you get one from FuelMoto, they will send you canned maps until you are happy. S&S recommends them...
You might have a conversation with your dealer and see if he will support any of the things that I mentioned, some will, some won't...
Just keep in the back of your mind about the "because it's a CVO it needs a dyno tune for just pipes BS"
Hell, I'm starting to sound like Jerry... LOL