I don't think that will do it. The formula needs to work for awards from
anywhere to $3,000 to $6m.

Lets say we have a $150,000 award. The formula would need calculate 3% on
the first $100,00, and an additional 2% on the remaining $50,000. The two
calculations combined would tell me what FEMA would be sending us for
administrative costs.

Lest say we have a $2.5m award. The formula would need calculate
3% on the first $100,00,
an additional 2% on the next $900k (between these first two steps, that
covers the first million), then,
an additional 1% on the next $4m (all three of these steps would cover the
first $5m), then,
an additional 0.5% on anything in excess of $5m

Hope this is clearer than mud.