Don't search so much for hate...Just, it's relatively rich americans living in a house the vast majority of native Tanzanians could only dream of..
It is not that simple. In the Anglophone countries, housing is part of the
remuneration from the employer, and many employers can afford $350
a month; also, remember, this price is a little higher than what a local
would agree to pay.
I am not sure about the statistics, but these are Americans are not rich
at all by African standards. In fact, other than the big house, they are
poor by African standards. Not only do they have nothing, they are also
unable to afford even curtains and keep saying "kidogo, kidogo", which
means "little (by) little". The poorest African would have chairs, a table
beds, curtains etc in that house.
Of course when you live in a foreign country the planning is different,
and it is possible that they have more money than they are showing, but
are wisely holding it for a rainy day.
That is what I would do.