I would think a situation in which 1% of individuals control nearly half of the wealth, that 1% definitely qualifies as rich. The top 20% controls 98% of the wealth. Is $8/h rich? Around here, were the cost of living is not high, $8/h will leave someone living on their own with very little and occasionally late on bills. And while many American poor do have more than the poor in Africa, many of the poor in America have nothing and can only eat that burger because of the generosity of another. Many of the poor in America only have a home and food because of the generosity of others and being fortunate enough to qualify for welfare (as many times, being male, not having a child/being pregnant, and making just abit too much for welfare but not enough to sufficiently provide for yourself often disqualify those who need help).
From a Biblical perspective, it seems that being rich means having enough money to make a difference in your community and being able to ease the suffering of the poor. It may also be having more than you actually need to live, as even a small amount of extra can help to feed and clothe the poor.