That problem will always exist in a game mode that awards players for being more experienced or playing better.
Any solution to make stuff balanced?
Maybe, we could add a loan system.
A player could take upto $50k loan, which makes his cash go in negative values.
For every -$1000, the player spawns with 1 less HP on every spawn until he recovers to a positive balance.
So, if I keep spending money and have -$27k, I'll spawn with 73 HP.