War memorial coins are big sellers. People buy them for various reasons and are willing to pay substantial prices to get them. Merchandisers know this.
These medallions are not coins, but modern souvenirs and gift items made to look old. They were not minted by Hitler between 1941 and 1944, but were produced in modern times from base metal. There are several patterns (Messerschmitt is shown) and some have other war vehicles such as tanks.
Collectors pay between $15 and $20 US dollars for these medals, but they are not worth that much. If you had one to sell, and you wanted to sell it to a coin dealer, the dealer might pay $1 or $2 for it.