How much cash needed to buy 1 offer going next arena?


I noticed, that coming level up on next arena, there is appeared good one time offer of DNA buying by cash. But nowhere i found info - how much is needed for every leveling up and buying this offer? Maybe those, who are at highest level can write this? 2nd Arena 500 points and 100 cash, 3d Arena 1000 points and 150 cash. 4th Arena ???


Here you go: