In places that consist of many people with subsidized incomes, like elderly housing complexes, why aren't local grocery stores and gas stations higher than elsewhere?
Also, aside from that question, prices will only rise if there's no competition. In a working market, if more people can afford a higher rent more apartments will be built.
Because “many” is different than all and these stores would otherwise not exist?
Because the subsidies aren't on top of base income?
The subsidy isn't the problem per se, it's the net increase in income.
It is obviously self-evident everywhere that high incomes create high cost of living, which can be traced through higher costs all the way down to the land rents (the rent someone is willing to pay to have market access to the high local incomes).