I have noticed that lvl 50 ability costs 1000g and 1000g is also the limit of how much money you can carry as lvl 50. I doubt lvl 50's want to get max money for getting a ability as all money extra goes wasted. So my suggestion is a change to the max money formula.
Current formula: [character level] x 20g
New formula: [character level]2 g
Level: (Current:) [New:]
2 (40g) [4g] - new players don't need even 4g
5 (100g) [25g] - If you gather and sell, you might reach the limit, but you can easily increase the limit
10 (200g) [100g] - At this level you get your first gem-slot gear and you don't need perfect gems on it
20 (400g) [400g] - At this level there is no difference between new and current
30 (600g) [900g] - +50%
40 (800g) [1600g] - double
45 (900g) [2025g] - max for non-supporters atm
50 (1000g) [2500g] - The currently known max level, at this level if you are not supporter you have to change your gold to EP, because it reaches the cap
Additional suggestion: Make a new sort of money - Platinum that's after the pattern 100g. The ore on lvl 64 could be platinum, but this would come with the fifth expansion, so it will take some time before that.