T. A. Gardner
Serial Thread Killer
That's about the price of such a stamp here in Washington too.
There is also an additional inspection charge for such high current installations. Don't know if they have that in AZ. That's a county charge here.
There's a nominal permitting fee--typically about $100 to $300-- if you go that route (eg., replace your service). It's hiring an electrical engineer that's expensive, even when you have one you use--and I do have a 'guy' that does that in Buckeye AZ who is semi-retired and works out of his house. The replacement of an existing service for a 300 amp + panel will run you anywhere from about $8000 up depending on the length of the underground pull, if that is the case (usually is) along with labor and materials. Anything over 200 amps in a residential panel is wholesale only and a lot more expensive.