I'm not that sure anymore, the AS transfer policy is being implemented and ASN16s will soon have a value once the free pool is depleted.
People have learnt from v4 that you don't give up scarce things. One day people will pay for them, and as I said the other week if you want to garbage collect them you'd have to charge a high price to make it worth giving up (or pay as others have suggested) and people won't vote for that. A 50 Euro fee is way too low to do it and a pointless complication to the simplified charging scheme. I also doubt the unadvertised figure gives the whole picture, some will be used privately (no idea how many). I think trying to retrofit other hand back schemes now is futile (it was hard to hand back once, back when people wanted to hand back) brandon