A different perspective
I know most of these offers seem agast to the recipients, but looking at it from the perspective of those who qualified by achieving the stated milestones, wouldn't most qualifiers be furious if the offers were for less than 100% of a recipient's PQP delta? What would the incentive be to qualify organically, if you could get a big discount by buying it in Jan?
For example, there's a 6000 PQP difference between Plat and Gold. Someone who just made Gold requirements shouldn't expect an offer that's less than the cost of 6000 PQPs, should they? If anything, I would expect these buy-up offers to be at a premium (>100%) since the traveler didn't qualify organically. I know there are cases above where the buy-up is vastly more than 100% which baffles me. But it also seems that a fair number of people are expecting to see discounted offers since no travel was involved, and I can see the logic in that argument.
Unfortunately, you can't buy status directly, except through these buy-up offers. At least not that I'm aware of. I did a segment run last year to hit my required PQF. On my way to the airport I told my wife that I wished I could just pay for the ticket and not have to actually go on the flight, but that's not how the game works. Was I smart or not to make a segment run? I dunno, because I qualified so I didn't get a buy-up offer. But my guess is the <$200 I spent on a segment run saved me from an offer that would have been based on the full PQP whereas I qualified on the discounted PQP + PQF.