Buy backs are acceptable (and SOP) if the administration is buying equipment from individuals for security.
However,
1) Individuals buying hard-drives from governments (for security) is very unusual.
Assuming it's purely security related, the other problem...
2) How is this NOT favoritism? These drives weren't auctioned off. They did NOT belong to Romney personally, they belonged to the state. If I can buy a drive, can I buy a computer? A boat? A plane? What price was paid?
When I worked as a Government Contractor, I was not allowed to buy *ANYTHING* except through an action.
But then again, Romney is a Republican. If Obama did this, you can bet people would yell.
(Hell, they yelled about Clinton's administration walking off with 'W' keys from the keyboards!)