SanDisk 256gb Cruzer Glide USB 3.0 flash drive with "up to" 90 MB/s transfer speeds for $32 after coupon.
Use Google Express coupon code WINTER20 on a "new" Google Express account for 20% off ($8 discount). If you have a Costco membership, add that number to your account first, to avoid the 10% access fee.
If you don't want to go through Google Express for the $8 discount, it's also available directly from Costco (in-store and online) at:
Reviews are all over the place (lots of bitching about speed), but for basic archiving/shuttling, this is a steal. The Ultra version (just 10 MB/s faster, with a slightly longer 5-year warranty) is currently listed for a hilarious $200 at Best Buy: