We charge for everything. I've gotten used to eating three times a day, having clothes on my back and a roof over my head. If you're questioning the need to charge for install you should rethink your program.
We price per linear foot and yes, install is worked into the quote as well. Couldn't quote on the spot though. It would have to be put together by a designer then see how they can best fit it into a cut file and then estimate time and distance to install. If you're shopping to undercut another sign shop good luck with that. We're not in that position. Yes, our prices are higher but that's how we stay in business.