UV codes worth more than physical disks?

[Sifox211]

I have Leon and The Fifth Element in the US pop art steelbooks and recently replaced the disks with the new releases. Along with these came UV codes valid only in the US.

I have no interest in these codes so decided to flog them on eBay (free listings for me at the moment so no risk), clearly marked as valid in the US only, starting at 99p.

Honestly, I did not expect them to raise anything much, but they just sold for a combined £12.50

So how is it that a UV code can go for more than a physical disk? Admiteddly I have not tried to sell the equivalent disks, but have been flogging a lot of stuff recently for a lot less than these babies fetched. What a strange world we live in