Finnair Plus sells its points at a bonus couple of times per year and its current 50% bonus sale ends today (June 5, 2017).
The sweet spot of Finnair’s award chart are the short-haul upgrades from Economy to Business class (Dubai is considered short-haul) that are priced at 10,000 points (sometimes discounted).
You can access Finnair’s page for buying points here.
Here’s the bonus schedule:
And here’s the price if you buy the max:
The price is 0.86 euro cents each.
I would only buy Finnair Plus points if I would be 100% sure to be able to use them for these short-haul upgrades where they are good value compared to paid upgrade prices or paying for business class outright.
Here are the the terms and conditions of this offer:
Transactions must be completed between 1 June (00:00:01 EEST) and 5 June (23:59:59 EEST), 2017 to receive the Finnair Plus Points bonus. Bonus Finnair Plus Points will be awarded to the recipient. All other Buy/Gift Finnair Plus Points terms and conditions apply.
A maximum of 70,000 Points can be purchased or received in a single calendar year. Purchased Points are not refundable and are applicable toward all Finnair Plus awards. Points purchased through the Buy Points program do not count towards Finnair Plus status upgrades. All other Finnair Plus Terms and Conditions apply.