$0.00
I did it myself.
Most shops are around $100/hr for just labor. It is best to call various shops and ask them how much a cam swap (and tune if you are going to use the shop) is.
There is an EXCELLENT cam swap how to guide on this site I have used a couple of times.
https://www.camaro5.com/forums/showthread.php?t=125123
If you DIY, I do suggest one of these to help install the front cover:
http://www.saccitycorvette.com/AlignItTools.html
Well worth the peace of mind to prevent leaks in my opinion.