I will try to do the "Cumulative mode".
(Edit)
I have an algorithm that calculates the prizes ( 0.9304783950617738 return over 1) from a prize table.
It's based on this:
i) Nothing (next level)
ii) Nothing (next level)
iii) Small price (0.10 ~ 0.35)
iv) Medium price (0.15 ~ 0.40)
v) High price (0.20 ~ 0.45)
vi) Higer price (0.30 ~ 0.80) and live (protection against ii).
I can send you the code (HTML + JavaScript), so you can play with it and adjust the prizes (you don't need special skills for this, because your web browser can execute JavaScript code).
Now, I will start the second mode.
I have finished the work and sent a PM. Do You accept escrow?
I left some values of the prizes table for risk mode (0.9319272976680386 return):
i) Nothing (next level 0)
ii) Nothing (next level 0)
iii) Small price (0.10 ~ 0.40)
iv) Medium price (0.20 ~ 0.50)
v) High price (0.20 ~ 0.60)
vi) Higer price (0.30 ~ 1.00) and live (protection against ii).
Like the previous mode, It's just a JavaScript with a prizes table that you can edit.
If You preffer the option to double/nothing, ask me, because It's not difficult to add it to the code.