SanDisk SDCZ48-256G-U46 256GB Ultra USB 3.0 Flash Drive - Black. USB 3.0 enabled (USB 2.0 compatible).
Not the cheapest according to Camel Camel Camel (https://au.camelcamelcamel.com/product/B00YFI1A66) but it seems cheapest at the moment? Can't find it cheaper for similar capacity with the usual candidates. Decent price IMO, if you can't wait.
Cheers..
In 2006 I lined up to buy a 1GB thumb drive for $49.
Man - that was cheap and huge!