Official Goldback.com exchange rate for 08/16/2023 remains $4.00 as it has not been updated since yesterday.
After a review of online sellers' prices, the best price for an in-stock 1 Goldback is $3.63 over at Defy The Grid
The best price for an in-stock 50 Goldback is $175.57 APMEX
https://apmex.com/product/255963/50-wyoming-goldback-aurum-gold-foil-note-24k