You can search this site (and mazda3revolution site) for discussions on getting navigation SD card on eBay for significantly less money than dealer price. I got one a few months ago for $45 when there were quite a few sellers for the cards at around that time. I figured it was worth the gamble as I thought I wanted to get a 2019\2020 Mazda 3 hatchback but ended up getting a CX-30 (they use the same navigation card). I don’t think there are as many sellers at the moment on eBay with the BDGF66EZ1 card, but I did see a few. Search for 2019 Mazda 3 and make sure it is the BDGF66EZ1 or BDGF66EZ1A card.