It works the same in Canada. Sales tax is added as an additional charge on receipt when paying – not shown in the advertised price in an or or on the shelf.Advertised prices in the US don't include tax.
I was in the Apple Store today in B.C. and the sales tax was 12%. In my home province (Alberta, next province over) it is only 5% as we only pay the Federal sales tax (GST.) Same listed price in both provinces. I’ll wait until I’m back or have it shipped – not worth the extra 7% premium to get it a week earlier.
The mini has always been priced at premium over the entry level mini since the original was launched.It is a price gouge because the bigger regular iPad is cheaper.