Good evening hivers and good evening to the splinterlands community ^^, I bring to you a reference image that I made on excel inspired by the original one from july 2020 made by 
I've been playing splinterlands for a month now and this chart has really helped me out, specially when renting cards. With the release of the new reward cards (that have a different DEC burn rate) I thought this had to be updated, so here it is.
Below, I added another table that has the different leagues filtered by tier and it shows the deck power requirement and also added the amount of quest chests you can get per day on that league (I believe this should be added into the game's league info).
The letters in gold represent the card's max level that can be played (if your summoner can), for example, below bronze league it says 3, 2, 2, 1, that would represent common: 3, rare: 2, epic: 2, legendary 1.
I hope this table helps someone out there, like the original helped me. Thanks for reading and if you want to support me, upvote me please ^^. Good luck and I'll see you on the battlefield.