Size a trade so that its stop costs a set share of the account, and see what it does at the stop and the target.
Budget $2,000.00 (2% of the account). Round-trip commission is counted in the loss at the stop, so it never exceeds the budget. Break-even exit: $100.02 a share.
For the trade sized above.
Your assumption, not a forecast. Assumes every trade ends at the stop or the target.