Adventures come in multiple tiers that each can be bought for gold or money. Also, there's an option to buy the whole adventure at once with a little discount.
If I managed to buy maybe one or two tiers with gold and then decide to buy the whole pack, will the price be reduced accordingly?
Yes, it will.
From past adventures, Blizzard was reducing the price of the adventure accordingly.
Generally speaking, the price is something along the lines of 5$ per wing. They keep the same pricing as long as it's not a single wing purchase.
So if you do plan on buying a wing with real money, buy 2. It's basically around 3$ for 700 gold.
