If A1 is greater than A2, the Replacement Cost or Total Cost to
Re-Build is the minimum amount required. Enter Required amount in A5.
If A2 is greater than A1, compare A3 to A1. If A3 is
greater than A1, the amount in A3 is the minimum amount required.
If A1 is greater than A3, then A1 is the minimum amount required. Enter
minimum amount required in A5.

Note: A3 is always 80% of A2.

Need formula for A5 that satisfies all criteria. Is that possible?