You don't need to add debt, or even money into the equation to complicate it. Lets use labor time (in hours) as our unit of account.
LH = composite labor hours (the labor hours required to harvest / produce the intermediate thing)
Input | Labor Hours
|
Wood for chair, IE materials | 1 LH Per chair cost of building factory, maintenance, other costs, etc | 1 LH Time to produce the chair (turn wood into chair), IE Wages | 1 LH | Capitalist sells the chair / Selling price | 5 LH
Surplus value = 5 LH - 3 LH = 2 LH
So the capitalist gains 2 LH
for doing nothing.
Maintenance, startup costs, materials, can all be accounted for in the selling price. The point is that :
- Workers do not receive the full selling price (after accounting for other costs), and
- Workers do not control the surplus, IE its capitalist-controlled surplus value. This is the theft / profit part.