San Francisco - Room to Grow Rent?

Is there room to increase rents in San Francisco? 

While the SF metro's average rent of $2,200/mo. is very high on its face, it's fairly low compared to the area's $115k median income (by far the highest in the US).

Avg. Annual Rent - $26,000 ($2,200 x 12)
Med. HH Income - $115,000

Rent / Income Ratio - 23%

Relative to income, San Franciso's rent is only slightly more expensive than the US average. And it's cheaper than markets like Orlando and Providence.

Would you invest in SF given how high the incomes are? Or would you stay away because of the high cost of entry?