So far I discovered that the best mission to collect coins on the new 2x2 campaign is mission 5, insane mode of Lost Valley.
with 6 refill credits you earn 7380 coins (real), while in the 1x1 campaign, with 12 refill credits you get less than 12,000 coins.
It´s also better than the insane mode of BB (at common campaign)
If you know another better one, please pass the notice … thanks!
- By the way, you´ve to try! because the numbers shown, are not the real numbers that you get. 7380 is real!