In the scenario local good is still worth $100 but given that you refund all good by the amount added by the tariff later, you have $20 refunded (not really $20 as i tried to show previously, but $20 x total_tariff / total_amount_of_good_bought_locally_and_imported, so somewhere between $80 and $100 net for local production and between $100 and $120 for imported good, depending on the ratio import/import+localprod