Yes you do.
You charge as much as you can, otherwise you are leaving money on the table.
Every business is constrained by what the competition is doing. Competition for clients makes you a price taker, not a price setter. You don't have a momopoly.
If your competitor worked under the table, cash only, no taxes, he could afford to undercut you and take your business. If your competitor paid higher taxes , he would raise his price, or his profit margin would be unsustainable.
All your costs, including taxes are a function of your businesses survival