50% ‘buy Avios’ bonus now on

As I understand it, the 50% bonus is on single transaction purchases of Avios, not on the subscription service and only on values of 5000 Avios and above.
If you purchase 200,000 avios this way you will get a bonus of 100,000 avios making a total of 300,000 and it will cost you £3,215
If you subscribed to the 200,000 avios subscription and boosted that with a single transaction for 105,000 avios (70k + 35k bonus) it will cost you £2,924
(£1,789 + £1,135)

With the subscription service you get the points trickled to you through the year though, with the single transaction you get the points in a lump sum so can use right away.

Hope that helps

It would be breathtakingly cynical if they then immediately devalued Avios straight after offering a bonus for purchase. It would probably also serve as grounds for unwinding the purchase transaction (you might be able to anyway for 14 days on the basis of distance sale legislation) and the close proximity between sale and devaluation might give rise to accusations of fraudulent entrapment leading to a class action court case. So no.