I'm on year 8, third company and will be looking for 4th over next 6 months, but there's no reason I have to change locations as I can change companies and get the career bump all in the same location.

We also bought knowing we'd get significant appreciation on our house in the short term, so with four years in our house we're still much better off having bought a house, even when considering closing costs (and would have been after 2 years even). But the market is different today than it was 4 years ago too, so the considerations are slightly different.