As for the suggestions ...
I have already proposed many of them, but I will propose again.
1) Remove RNG, if you want to earn money, set high prices, but save our nerves and don't gamble, it's not a casino
2) Eliminate most of the stones, there are way too many of them
3) Add bonuses for having a full zone !!!
4) Add cards from mirrors, mill from logar
5) Start introducing cards from the rest of the maps
6) Add cards to hard inis that don't have any
7) Go back to the old values on the cards
8) Lower the prices of the orange stones
9) Allow the stats in the cards to be sorted in order
10) Remove the idea of rising prices as you buy
11) Power up the old cards that gave +25/50 to all attributes
12) Boost cards from new WB !!!
13) Add damage cards, it doesn't have to be a lot of value, maybe from mirrors
14) If I know malatina, goblins etc don't give cards, add them, let a nice bonus appear there
15) Allow all cards in the Silver Spring to be upgraded
16) Add a Card Score parameter or something like that for the ranking and compare with other players
17) Let the stones that improve the attribute by 0.1-0.3 points be better and cheaper because the current version is absurd
18) Again please delete this rng
19) Focus on making this system easier, not complicating
20) Just read all the posts in this thread again
EDIT:
21) Maybe it is worth adding healing power points (small values) so that there is more to improve for the heal, besides wisdom?