Asynchronous trade: Unique map gold costs are insane

Why do unique maps cost multiple thousand gold to buy? On most unique maps you CANNOT make this gold back so you esentially have to pay currency AND alot of gold to do these maps.

This is especially egregious with Synthesised Maps which cost 9-10k gold... even with the full Synthesised map pack size wheel I barely make that gold back after fully clearing the map which is a waste of time due to a lack of loot.

Why is it that I have to pay such a ridiculus amount of gold to fight the Synthesis bosses when all other boss maps, i.e. Shaper/Elder guardians or conquerors, only cost ~1k gold. Even acessing uber bosses only requires 2.5k gold for the 5 fragments total.

This is especially bad because it is currently impossible to buy Synthesised maps in bulk through the trade website where the only choosable Synthesised maps are of the wrong map tier.

I don't want to have to sit 10 hours in my hideout whispering 1000 people for synthesised maps, only to get a single response and oh... he only has a single map to sell...