Maybe it's just the wording but I don't get that. If they're paying enough that 2.5M is within reach where it wouldn't be in Phoenix is it really a problem?
I'm in the middle of a job search right now and I'm finding that while absolute numbers sound appalling (ie. 2.5M for a 2,000 sq.ft. house) the income:COL is not as dramatic. I rent, but so far places that have high-end apartments that cost 2x what my current one does pay about 2x more (usually even a bit more) on average.
To me it comes down to wether you'd like to live in Sunnyvale or Phoenix as long as the companies in both locales are paying enough to afford comparable housing (I wouldn't expect identical square footage). Remember we're talking about a 2.5 Million dollar home 1 mile from what is probably one of the most advanced tech campuses on Earth (and probably has some of the best paid).
When you put it like that I don't think it's hard to see why some people would sacrifice a little square footage for living and working at a place like that over Phoenix in an instant (I know I would).
The point is that even a 3.5M for the new house will be a lot, but by virtue of it's location and salaries at Apple it's justifiable
https://www.redfin.com/city/19457/CA/Sunnyvale/filter/min-lo...
2,5M, with respect to the existing market, doesn't appear to be out of the norm.
The idea being Sunnyvale can justify that with salaries and the employers in the area
You are not buying this with a $150k salary.
There is always the potential for a crash in the housing market, but it can also end up that the $2.5 million is a winning investment (as compared to being spent).
You can get a decent house in a nice location for $400k in Phoenix itself.