Yet, when I was a smoker and bought my cigarettes in Missouri and brought them back to Illinois to smoke, Illinois wanted me to pay Illinois tax on them, the same for the liquor tax.
Basically, ALL states that have a Sales and Use Tax do this. The Sales Tax rate and the Use Tax rate are exactly the same. Many states leave it to the citizen to come forward.
When an item is purchased in Missouri and not exported (by the retailer) then Missouri sales tax is due. When the customer takes possession and brings the item(s) into another state (Illinois) then Illinois Use Tax is due.
Say, for this example, Missouri sales tax is 6% and Illinois tax is 7% then the individual would owe Illinois the additional 1%. However if the Illinois tax is less than the Missouri tax there is no refund.
Been that way for decades.