Hi,
I noticed numerous times that prices and discounts of some games change throughout the day.
Example:

Heroes of Might and Magic 5

Yesterday morning it was 3,99 €
Yesterday evening 4,99 €
This morning 3,99 €

WHY?
Is it some location/currency market thing?

I noticed that on other games as well during several sales from GOG.

EDIT// I just checked the pricing on HoMM5 again it is up to 5,00 €again... I bought it minutes ago for 3,99.... how???

The Might and Magic series currently have a special promo. By default, they are discounted by 75%. If you buy 2 of them, you get an 80% discount and if you buy 3 of them, you get an 85% discount. Even though you might see a 75% discount, it will correct itself when you go to the checkout.

And a link to the promo

Heroes Chronicles and Crusaders of Might and Magic not included.

Bundle prices are wonky on GOG.
* They are often not applied on listings outside of the promo page.
* They are often applied incorrectly on the promo page itself. (some promo pages apply the discounts before the required number of games
* The game listing may start with the unbundled price and correct itself to the bundled price
* Due to the vagaries of currency conversion and GOGs preference for rounding stuff up to end with a 9, when the bundle discount is applied you can have a saving of exactly zero dollars and zero cents.

Checkout is probably the only place where they get reliably triggered.

Ok, thanks.
Didn't know since I didn't see any indication as to why that is. But now it's clarified.