There are 2 main things you have to decide before doing any change...
1. For the current player that already upgraded their pillars and shit - If I am one of them, (I already upgraded 13 pillars....) I will not feel good, since the price suddenly drop down, and all efforts I put in would become useless.
2. For the new players that are dying to upgrade their cards - For me and my newbie room m8, most time we spend on this game is endless grinding...for PILLARS... however, the current grinding speed is ok, everyday, you can upgrade around 5-10 cards, depends on the time you spend in. From 0 to a FG slayer deck, it takes around 1 hr only, once you can kill FG, especially the easy ones, each card win = one upgrade. And, one facts about human...sometimes people DO LOVE grinding...
Personally, I do agree half of it, change the price, however, not reduce card upgrading cost. If a change has to be made, I prefer a card ranking system, so that different cards costs differently to upgrade depending on their rank. For example, weapons costs 2k or sth to upgrade, creatures costs 1.5k - 3k depending on their popularity/rareness/power
and Pillars... I do hope to get a reduced price, say 1k for pillars...
But, it's just an idea, I personally believe that the current Elements are more than expected~ THANK YOU FOR THE CREATOR!!!
Maybe if you really wanna spend time on thinking this, I'd prefer to think about new cards. For example, something to destory Opponent's hand~ Or, steal a creature. And also, I'd like to know something to keep us attracted in the game, such as new playing style, or even a 2v2 play, or other, and easy accessible, by just couple clicks, since I found out that once you got everything... It become boring.