In SF, $35/walk is cheap. If you've watched 10hrs of dog training videos on youtube you can command $100/hr (the going rate for an unqualified dog trainer), or $150+/hr for a qualified dog trainer.
I'm not trying to be silly, I guess I should watch one of those videos but I can't imagine not being a pro dog walker my very first walk? I guess I have the complete wrong view of this job as "low skill".