Isn't that double counting? In the first scenario, $2252 is the amount that they get in their bank account post-tax (marginal). In the second scenario, they get

Isn't that double counting? In the first scenario, $2252 is the amount that they get in their bank account post-tax (marginal). In the second scenario, they get $0 in their bank account post-tax (marginal), and there is a deduction but that occurs on the amount donated so they don't really gain $1459 but rather avoided paying those taxes.