The second part is alarming, but offering a temporary discount is a routine and standard pricing strategy; not a 'bribe'.

I didn't mean to say it was illegal, I meant to say it was an advantage in competition against the open-source counterparts because those usually cannot afford to make discounts of any kind.

More concretely, Microsoft used to claim that the price of their software is compensated for by the operational costs (which is false, but they managed to convince a lot of people).

In the same way, due to having deep pockets, Microsoft can, temporarily, operate at a loss only to out-survive the competition only to crank up the price to the ceiling once the competition is gone.