If you only paid $100,000 and you made $1,000,000; you’d have $900,000 profit; of which you’d probably only see ~60% to ~40% of, if Capital Gains taxes are anything near what I think they are. If we assume a “worst case”, where the Federal Government takes 40% and the State takes about 20% more, that means your tidy profit is only about $390,000. That means you’ve probably got to secure another $140,000 in financing on average to pick up a more modest $500,000 home (in today’s market) to retire in.
Capital gains taxes range from 0-20% Federally, depending on your income. In Cali, the addition is up to 13%
Which means that worst case scenario, you sell a property in Cali, you would pay 33% of the profiit above the original price of the house and the 500,000 exemption. So on a house you bought for 100,000 and sold for 1,000,000, you'd pay the awful, awful price of... 133,000, leaving you with a paltry $867,000.