The bringer of rain mechanic question

The BoR has 3 support gems built-in. I was wondering if your mana cost of your active skill gets higher by the multipliers of blind, faster attacks and melee damage. I guess they are, but I want to be sure so any owner of a BoR can easily confirm me this.

Btw, I would like to buy one. I don't have any wealth though, just a dozen of low level uniques, some chaos orbs, orbs of regret, orbs of scouring and a 10% quality molten shell.

you wont get one for that what you have, they are pretty rare and there is a high demand for it. So they usually cost 8-10 ex and thats not a ripoff, because you dont need a chest piece anymore which would cost 10 ex min if you want 6links.

and yes the mana costs get the higher multipliers from the inbuilt support gems