Not just SV, but almost anywhere in the US at this point I would imagine. I was working support in the Phoenix area back in the mid-90s' and it paid roughly 2-3x minimum wage at that time. While the ratio wouldn't be the same, a lot of places now have a minimum wage in the $9-12 range. Given that, $20/hr+ wouldn't be improbable for first line email/phone support.
A couple of years ago I took a break from IT to work first-line support at a local (midwestern) software company. Hourly rate was just a little over that minimum wage range, nothing near $20hr though. I was glad to get it, glad for the experience, and glad to go back to IT when my time was up.
In all fairness, support costs also include all of the techs' phones, computers, networking, software licenses for Teamviewer et al, and office overhead. So a $20/hr bill is pretty cheap for a minimum wage technician.
