I made from 0.3 -> 5 BTC in 10 hours with martingale on PrimeDice.
It were so freakin crazy.. that "ride" raised my total wagered to 113 BTC.
Then I cashed out and lost it all back 3 weeks later..
My highest bet were around 1.25 BTC.
Martingale is always a losing strategy in the long-run.. if you don't have unlimited money supply.
If you have unlimited money supply, why would you need "More" money? You already have unlimited.
Also, no, even then, the expected value is still negaive.