Some advice from our member CHAPEL:
Anyway, yea for emailed tunes, those prices look way to expensive. Unless the price includes an actual brand new hand held tuner device and life-time tune updates for future mods. Dyno tunes from what I can remember usually cost around $400 - $600 for simple bolt-on mods. Supercharged, aggressive cams, turbos, nitrous, etc, usually cost a little more.
The way most newer cars are tuned these days are with a hand held device uploading either a canned tune or a custom tune into your ECU. When you want to return to the stock tune you would simply flash the stock tune back into the ECU via the OBD2 port. I believe some tuners use a device that plugs into your OBD2 port and stays there. When you want to return it to the stock tune you would simply unplug it from the port. So there are different ways to tune. HP tuners, SCT, and Diablosport seem to be the more popular and more widely used tuning programs out there.
Your best bet would be to find a company that uses the handheld tuner you prefer. Make sure they are reputable and have been around for a while. And make sure that whatever tune they have you datalog so they can make sure the tune is right for you. Here is how it works...
A tuner should write you a custom safe tune based on the car and mods. After you flash the tune in, you drive the car for whatever amount of miles they specify so the ECU can learn the tune and the mods. Then they'll have you datalog certain parameters at certain speeds. You then email the datalog to them, they view it, and make any necessary adjustments either to correct the AFR or to get more power out of it. Then you'd do the entire process over again until the tuner feels that the car is running at its optimum for the mods you have. It could take a few different tunes before it is perfect. But you do not want a tuner who just gives you a custom tune and sends you off without checking it and seeing if it needs adjustment.
I hope this info helps. Make a few calls to different places. See what they have to say, what deals they offer, what their prices are, how their customer service is, what tuning programs they use, and take some notes. If you have any questions or are confused about something then do not hesitate to ask them to clarify things. And feel free to ask me as well and I'll try to help as much as I can.