I have not dealt with him specifically, but shipping costs add a bunch, so if you have someone good locally it is good.I've got a 462, and like it a lot as well. I had never really considered having any porting done on any of my saws, and I really don't NEED to do it, as I'm happy with it's performance now. But just for s#$%s and giggles, I might get mine ported. What is the ballpark cost of sending one out to like Jason Egan, or somebody like that to have it done?
The porting costs, which generally include machining the cylinder and porting it will usually cost several hundred bucks, so it is not cheap. (If you have ever watched it get done, it is a lot of work).
The 400 and 462 both run very well stock, and you can improve them a bit with a muffler mod, but having about 20% more from porting is priceless! Keep in mind that if you make the saw stronger you should also make sure you run good oil at a good ratio as there will be more stress on the bearing and piston surfaces.
There is a guy on another site who dynos the results, so you can see the difference (with numerous saws) if you wish.