Well, I don't really understand what you're saying there? Are the values below the initial values, or are they what you are getting after the calculations?
Most importantly, you should not be directly multiplying to BP, as that obviously modifies your variable. In other words, if 1000 is the initial value for BP and you then go through that calculation, the new value for BP will be whatever you get as a result, so when you run the calculation again, BP will not be 1000. That is probably why it reduces to 0 after one iteration.
In any case, you stated your desired formula as:
(BB (SB+AB) / RB) BP
The order of calculations listed above does not correspond to that. Remember BEDMAS?
What you would want to do is create a new variable (I will call if DV, or Dummy Variable) and this is what the calculation should look like to match the equation above:
DV = SB
DV + AB
DV / RB
DV * BB
DV * BP
That would give you the sales price. To then get the income, you would:
DV / 100