Three different values
The spread is the difference between the buy and sell price. A commission is charged separately under the account terms. A rebate is a later cashback payment subject to its own terms.
Use the same basis
Compare the same instrument, position size and account type. Do not combine a spread or commission with a rebate measured in a different unit or on a different basis.
What DualNet data shows
Broker pages list rebate rates recorded by DualNet for each broker and account. They are not live spread quotes. Check the broker’s official terms for spreads and commissions; use the calculator for rebates.