I'm not saying there's no need for an FPU (F as in floating)! I'm saying that you don't need a special fixed point unit.
With "cents" I meant the smallest unit in your currency. I don't have USD in my wallet
well you have interest rates , money value proyections, devaluation, inflation, investment rates, taxes, deductibles, loans, etc. but at the end is a problem of quantity, this marginal errors won't be a problem for 100.000 transaction but for millions of transactions/per hour it grows to a big number, big enough to fear litigation that will cost you much more than just get an IBM power system to keep them under control