I would really like to know why is the Expansion pass NEVER get's its price reduced during promotions? I've asked Gog countless times, yet they refuse to give me an answer. Furthermore, the price has even inscreased in the past weeks/month. The game is 1 1/2 year old, not to mention there is a GOTY edition.

Why would? Their products , their price, usually thiis mean that it still sell good, no need to price drop...

I doubt very much that you've asked "countless" times. In any case, why should they answer you? They don't owe you an explanation of their pricing policy.

I asked the same question as well, and no answer.

Keep asking is what I suggest.

Here is my posting about this: https://www.gog.com/forum/the_witcher_3_wild_hunt/expansion_pass_discount_request_for_those_who_already_bought_the_game

So your logic is: If my product sells good, I will increase it's price for more people to buy?!

Ok, I see you are mad because some other kid don't want to give you his toy, let me put this way:
1. I didn't told increase, I told not drop, they(CDRP) never increased the price.
2. This is capitalism, where each one it is free to put his price on his product, not communism, where the quality was dropped, so all nation get the product(I know, I've been there)
3. They are not first to do that(see Mass Effect 3 dlc prices)
4. I f you look closer to the history of company, you will see that now, most of money from this game help to pay the development of the next game
5. I don't say it is right or bad, I just don't complain about it, don't like don't buy, easy.
6. If you don't value their work with actual price, that don't mean that they just drop the price just because you want(btw I preoredered and don't regret the full price I paid)...

...and so on