Pc build embaressment

so hi first time poster here on the forum thought I would let you in on the small failure I had on my first pc build.
now its in currently in the works an well kind of hit a stump of a issues with fans....basically thought hey research the motherboard the chipset (lga 2011-v3) and the case (corsair obsidian 900D) everything else kind of falls in to place but boy was I wrong.
so yes I kind of used the motherboard ( asus rampage v extreme) and the pcu (Intel !7-5820k to figure out power and kind of roped that in along side the cooler for the next buy an well I keep rolling over what I want for a graphics card but it narrowed down to three choices.
now I choose today to do a better review of the case then the one I did on arrival to be sure it wasn't broken in shipping since its heavy. I have been reading the motherboards manual over picking out even more details proving I would be happy with it and boom I look at the fans supplied by the company for the case (900D) an its a 3 pin pwn while my motherboard( an the cooling monitor they supply) our four pin headers. the fan control system the motherboard comes with an the fan controller I planed to get from corsair( an basically everyone on public market) our now useless being I can ramp down an up easily with the integrated design I liked a great deal for cooling not sound.
now I didn't panic till I think about the other computer( the one I am using and gaming on) someone gave me to restore and us an others I have fixed have all had three pin connectors....even worse I'd never seen a four pin before or knew the gain till now.
course I am looking to get the fans I can use with the system ( all so far there in the high end price range) an thankfully the radiator I want has a nactua fan set with 4 pins so even that hasn't been a issue.
none the less not backing down I well fix this problem and get me system working by the end of this year( I work retail so money is tight) but the warning is make sure you do your research to a micro level.
anyone know a place to buy 120mm fans below or at $12 per?

Hi, welcome to the forums.

You can plug three pin fans into four pin headers, the fourth pin is not always needed.

thank you.
I just...kind wanted to use the features the board has to maybe ramp up the airflow.
none the less if it looks like price wise I can't afford the fans I won't by the 4 pin ones for maybe more then 5 spots in the case found some cheap one from the "antartic" company just want to look at there pressure rating first when I am not feeling foolish.
maybe they well do a video of don't do this now or take another look at the rampage v extreme board an make suggestions.