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several brands of external drives available. Few other device could use or need the speed...or absorb the extra cost.

You are in looking in the wrong place to save money if you are on a Mac and wanting to do Thunderbolt. ;)
 
If your mac got usb 3 , use usb 3 if you just want to use an external drive.
Hard Drives run not even close to the limits of usb 3.
 
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