Whats the relative value of the event boosts?

I took a break from the game after the event that offered ability sets 2-4, with the credit cap i now have i should be able to get the 900 points needed in this even to get max medals but since i was not here for the past 2 events namely double chapels and extra stat nodes i am wondering what order i should buy the upgrades in.

So my question to more experienced players is what is the relative values to my chars overall power lvl of these 3 buffs?

Extra stat nodes vs Double Chapels vs 30% Item Boosters

Keep in mind that i have none of the above buffs but will have access to 6+12+18k medals so a total of 36k medals to spend on buffs, i am looking hopefully for an order of priority so i can pick as many as i can up now then work towards the rest as i farm/deposit funds.