I am just going off of quick memory so I might not have everything perfect here. I hit something like 7 Hot Balls or you can call them Cash Balls if you like. Like I say I really don't have the time to break it down but I was on a Bingo Play for some time when it cost me 50 cents total to validate all cards in a short field. Next it depends on how much value I am getting for my points which has been up to 8x the amount compared to cash back so let's say I'm able to get 100 cash back or take 800 in Bingo. Sometimes I am buying some package deal with large amount of rainbows and sometimes it is just maximum blue cards. It depends on the promotion or what is going on and how many total number of cards are in play.
I don't really have the time to re check the total amount of cards. It has been almost a year and a half since I messed with Bingo so forgive me if I have this number wrong. I have been on plays where I have used my points and it has cost me 25 cents or 50 cents to validate playing maximum cards. What do I know? Obviously nothing if the Wiz is telling everyone never to validate.