> nice to earn $120k in Silicon Valley > $3500/m rent for a 1br apt

I think you are a bit off on both :)

Salary:

As a Software Engineer, chances are you can a bit more (especially including bonus + RSU). If you're "senior" you can earn quite a bit more.

Also: There are tons of other small perks that add up (phone/internet reimbursement, free food, public transport pass, free electric car charging, ...)

Rent:

You can currently get a 2 BR, 2 BR in Mountain View for about $3500 (managed newish building 2 minutes from Castro)

(Source: moved to Valley from Europe via Boston)