Buying rando BU ASE much cheaper than buying specific years?

I don't get how Ampex is selling specific BU ASEs for certain years, eh 2012, for $5-10 over a 2016, but then buying rando years is the same price as a 2016 or maybe even a few cents cheaper.

I bought rando and got ASEs over the last few years - can I now sell back to Ampex for profit or sell elsewhere for profit? I don't get the price difference.