Here is what I would do.

Since the housing price is pretty much the same between San Jose and Irvine, then the move is a sideways move.  You should buy a house in Irvine with 50% down payment and borrow $450k if you can.  The mortgage should be around 4.5% for 30-year fixed?  You will also get the deductions from your income returns.  The rest of $450k you can use the dollar cost average method to put them into the equity market.  70% of the money I will put it into total stock market index fund, 20% put into international fund and 10% for you to play in stocks.  The long term market returns should beat mortgage rate easily.  Good luck.