We don’t accept bills larger than $20, gold bars or heads of cattle for payment. [emphasis added]

$20 < gold bar < head of cattle

Redundant. The second two are already larger than a twenty dollar bill.

The dimensions of a dollar bill are
6.14 inches in length and
2.61 inches in width along with a
thickness of 0.0043 inches.

Size of a standard gold bar:
7 inches ×
3⅝ inches ×
1¾ inches

(Cow head, lol: ~20in³)

Head of Cattle:
Height: 62.2”-67.3”
Width: 23.6”-25.6”
Length: 93”-98”