Some salaries would give you an option for some decent backyard not so far from SF, but I'd have very hard time believing most Reddit developers would get such salaries, unless Reddit intends to significantly beat the market prices. Of course, the situation for 23 yo with no attachments and for 38 yo with a family may differ significantly. I don't know how their team looks like but unless they are all unattached youngsters with no families and no other ties to their locations, 100% retainment under this condition is a pipe dream.