I would really like to purchase Baldur's Gate 3 but it never seems to go on sale. Why? Why is that the case?

Because it had a ridiculously huge success and people are still buying it at full price, so the devs have no reason to lower it.

It was on discount (albeit very small) couple times already, last during recent Summer Sale.

It does go on sale.

But still not at a price that makes it worth buying.

It's only a year old. Games this new usually don't go on sale.

Its very niche - few people have ever heard of it and you may have to make your own graphics card to ensure you can play it.

Not true. The game was -20% discounted during GOG's summer sale.

Haha, love it.

For anyone new to the forums, don't waste time on this thread, here are only two of the many reasons why.

https://www.gog.com/forum/general/am_i_the_only_one_that_actually_still_remembers_this_1999_game

https://www.gog.com/forum/general/what_stops_me_from_simply_making_a_highend_graphics_card_myself_by_copying_nvidia_in_every_way

You know what? You can buy BG1 and BG2 for cheap price, combine them and have BG3 as a result. Since 1+2=3.
You're welcome.

Why do you think it's not buying? I am asking a genuine question?

The answer from Enebias essentially covers it already - the game is so popular that it still sells well at full price. I also would very much like to get the game at some point, but I expect we will need to wait at least a year or two more for bigger sales.

Because it has a turn-based combat system xD

Moreover Larian games never get high discounts too early. It was the same with Original Sin 2.