No. Tax is on the cost. If the good sells for $100 and cost $10. Then 10% additional tax increase the cost to $11. If the vendor decides to keep the same profit

No. Tax is on the cost. If the good sells for $100 and cost $10. Then 10% additional tax increase the cost to $11. If the vendor decides to keep the same profit, then the price goes up by $1, which is 1%