[jedberg]

The sales tax is collected after the transaction, so price elasticity has nothing to do with it.

What you wrote applies to other things like an increase in rent or property tax, which has to be built into the cost of the product. But it doesn’t apply to sales tax.

[forapurpose]

I'm not sure what you mean - would you explain? To the degree demand is inelastic, the seller will pass on the cost of the tax to the buyer. The buyer knows what the final bill will be, regardless of when the government collects the tax.

(Also, when I buy things in U.S. states with sales tax, the tax is on the bill and even if it's not part of the advertised price, I expect it and it's part of my purchase decision. People regularly cross state lines to avoid sales tax.)