The big question (for me) is why you need to copy it to a USB stick ?
These days it is getting easier to buy 160, 250, 320, 500, 750 or even 1000 GB of external storage at 'knock down' prices. 3-4 months ago I paid about 80 pounds for a 1000 GB (1 TeraByte) external Western Digital drive.
I just took a look at Ebuyer. For the sort of cost of 3 or 4 USB sticks (30 to 50 pounds) I found these:
48.99 Toshiba 320 GB portable drive
45.99 Freecom 320 GB mobile drive
45.00 Iomega 500 GB external drive
39.99 Hitachi 320 GB Portable Drive
37.95 Fujitsu 250 GB external drive
Some of the "portable" drives are meant to be a little more "rugged" but cost more. I have included them because I don't know whether you want to move large numbers of music tracks or films fromone place to another, or just plan to use storage as a backup of your PC/Laptop.
I suspect some are counting on their brand name (like Toshiba) to get a sale even at a higher price. Iomega has been a storage firm for a long time, alongside Western Digital and someothers, but Iomega made the Zip drive and SparQ drive before touching hard drives. The bulk of drives for companies will be made by the top three or four manufacturers and just given different serial numbers.
I have not checked the detailed specifications for the above drives, but felt they represented reasonable value for money - if you look on Google Shopping youmay find others on offer a little over 50 pounds but storing 1000 GB. I just did a search on Ebuyer (but you could compare with Dabs, Argos, Comet, Amazon and others).
One bit of warning - there are lots of empty external drive holders (enclosures) in the 20 to 40 pound bracket and disk drives at similar prices, which would fit inside, but you'd be paying say 25 for the enclosure and 30 for the drive. The ones I listed above are complete enclosures with drives inside, so are better value even if a bit more cash than some you may spot if you search for 'external hard drive' for example.
I hope you can see the way that having 3x 16 GB sticks is more expensive than say 250 GB on one disk drive. More portable, I accept, but much more per GB in cash terms.