If I understand correctly, the starting gold by level would go like this, then:
1: 100g
2: 780.4 (100 + .9*12*63)
3: 1741.6 (780.4 + .9*12*89)
4: 3113.2 (1741.6 + .9*12*127)
5+: as DMG
If that's what you meant, I vote YES.
That is indeed what I meant.
Now that I look at it, the DMG for level 4 is 3200, so maybe we should just say level 2-3 and use the DMG numbers from then on. (Which is right back where the proposal started!)
I don't want to muddy the water when there's already a proposal out there, so maybe I shouldn't even mention this, but in hindsight I would have proposed:
1: 100gp
2: 780 gp
3: 1750 gp
4+: DMG numbers
That keeps the numbers more even.
1: 100gp
2: 780 gp
3: 1750 gp
4+: DMG numbers