Every exchange has a different fee structure. To make it easy to estimate, assume when you take liquidity, you will pay $0.0030 per share and when you add you will receive $0.0020 per share. Min ticket charge on tiered is $0.70 and $1.00 on fixed. So it depends on the number of orders you have under 200 shares, how often you take vs add and your total volume. The best thing to do is pick one and forget about it for a month. If you think about it at every trade, it will cost you money on getting a good execution. Then export your trades at end of month to an excel compatible file and compare what they charged you with what the other structure would have cost.
Unless you are trading a lot of stock, it most likely won't be material.
Unless you are trading a lot of stock, it most likely won't be material.