plenty of people support a family on $60k/yr so take the remaining 440k minus taxes and buy two porsches outright. You should be able to save enough for a down-payment on each house given a year of saving.
that's besides that point? When you quote 500k/yr salary that typically includes perks like insurance. But are we really quibbling about $20k in expenses on a 500k salary? Even if I grant you 80k/yr to run your family that still leaves more than enough for your two porsches.