Ask HN: How to find a mentor/tutor for independently learning math

I am trying to independently learn mathematics at an upper-level undergraduate and first year grad student level.

Occasionally I feel that I need someone to just bounce an idea off or to ask for some clarification. I submit questions to stackexchange sometimes, but the format of the site discourages the vague and often ill-formed questions that I often have.

Do you have suggestions for how to find someone who could help me? Should I offer to pay a math grad student at the local university? Should I try to find a willing professor? Other suggestions?