At first I thought this was a terrible idea because it encouraged a pay-to-win environment
Now, I'm convinced that this might be a welcome addition to the game if some tweaks are made to it. For starters, scrapping the whole "Buy stances with money" and instead allow players to unlock new stances when they achieve x amount of qi (Reach a certain belt)
Let's say that there are five different stances:
Stance A: Default Stance
Stance B: Unlocked at Blue belt
Stance C: Unlocked at Black belt
Stance D: Unlocked at 2nd dan Black Belt
Stance E: Unlocked at 5th dan Black Belt
Later stances will only be able to be used against players of similar belts or higher to prevent newer players from becoming too confused. Earlier stances are safer, while later stances are more geared towards risky maneuvers such as starting upside down, which allows you to open with a helicopter kick of sorts
If it's developed this way, you might be able to think of stances as openers. For example, a shovel in Aikido or a snapkick in TK might appear as cheap tactics but they can be easily countered if you know a how to. Similarly, if you know that a player likes using x stance and use x opener, you might use y stance with y opener in order to counter that easily and gain the upper hand.
Newer players who watch higher-ranked belt players fight might find those openers to be extremely enticing and may be encouraged to buy qi or boosters, if you're really set on generating some money for Nabi.
Thoughts?