My go to was once it turned into troubleshooting I said "$55 an hour, that's my rate". If they said "why so expensive?" I'd follow up with "because I don't want to do it." Usually got a laugh and if they were actually willing to pay then they actually needed help, not just "why computer no computer gooder"

Probably made me look like an ass a few times, but I'm at the cookout, I don't wanna work on your busted-ass Chromebook from 2013. I want to hang out, eat a burger, drink some beer, and not work.