SanDisk Ultra 400GB MicroSD XC Class 10 A1 UHS-1 Mobile Memory Card up to 100MB/s read speed (SDSQUAR-400G-GN6MN) with Dual Slot MemoryMarket MicroSD & SD Memory Card reader - Walmart.com
SanDisk's 400GB MicroSD card is just $30 on Amazon
SanDisk 400GB ImageMate microSDXC UHS I Memory Card - Up to 150MB/s - SDSQUA4-400G-Aw6ka - Walmart.com
Amazon.com: SanDisk 400GB Ultra microSDXC UHS-I Memory Card 100MB/s, C10, U1, Full HD Works with Nintendo Switch Neon Video Game Bundle with (1) Everything But Stromboli Memory Card Reader : Electronics