So all that new Facebook money will be competing with the rest of us for the limited supply of homes and apartments. Even if you’re that luxury car dealer watching your sales go through the roof, the kid you just sold the Lamborghini to will outbid you for that home in Woodside. Rising home prices and rents – good as they are for current homeowners and for landlords – raise the cost of living in the Bay Area. That means that businesses across the Bay Area will need to pay their employees more to keep up with rising housing costs – or decide to conduct their business elsewhere.

These are by no means new challenges for the Bay Area. Steady demand for housing, combined with tightly constrained supply, has kept real estate prices in the Bay Area – and in much of California — among the highest in the country for decades. Before this recession, when people in the Bay Area said “housing crisis” they meant a shortage of affordable housing. The recession and drop in home prices pushed concerns about affordability into the background, with foreclosures and overbuilding taking center stage. But as the Facebook IPO sends home prices higher, we’ll look back at today as the day the Bay Area stopped worrying about falling prices and remembered how expensive it is to live and do business here.

Jed Kolko is the Chief Economist at Trulia, a real estate resource for homebuyers, sellers and renters, where he leads housing research. He translates economic trends and public policy on Trulia Trends, helping people understand what really matters in housing. Find him on Twitter at @jedkolko.