I’ve been watching this Sandisk 128gb usb3.1 flash drive for awhile and now it’s slightly under $18.
Good for temporary use and space saver.
Please check reviews from previous post.
Update: 128GB, 64GB offers expired. 32GB $9 still available as of Jun 1.
Had a few of these over the years, be warned they always seem to run very hot (eg burn your fingers if you touch the metal when you unplug it hot). Fine for transferring stuff quickly between computers but I wouldn't leave one plugged in for along time or rely on it for backup etc.