256GB SanDisk Ultra USB 3.1 Flash Drive (Black) for $45, 128GB for $22.99 & more at amazon.com

Amazon.com has the 256GB SanDisk Ultra USB 3.1 Flash Drive (Black) SDCZ430-256G-G46 for $45
Also, Amazon has the following 3.1 Flash Drives on sale:

SanDisk 128GB Ultra Fit USB 3.1 Flash Drive – SDCZ430-128G-G46 $22.50 -> now $22.99
SanDisk 64GB Ultra Fit USB 3.1 Flash Drive SDCZ430-064G-G46 $14 (possible extra 5% off coupon)

SanDisk 32GB Ultra Fit USB 3.1 Flash Drive SDCZ430-032G-G46 $8.88
SanDisk 16GB Ultra Fit USB 3.1 Flash Drive SDCZ430-016G-G46 $6.99