Some 40 years ago, I had my first experience of "international" travel , - Ferry to the Irish republic. Iwas curious about the fabled "duty -Free" and duly investigated.
Savings were minimal, so I didn't bother.
On my next trip, I bought the maximum allowable, to take into the Republic, having previously established that spirits in the Republic , were about 3X "duty-free"price.( IIRC, allowance was 4 bottles)
My favoured customers were delighted with their gifts. Me- I returned to UK empty-handed.
buyer beware, indeed....you won't get me fighting over duel pricing, or even finding me debating the savings on dual pricing.
I resolutely refuse to pay "ransom" prices in any "closed" situation such as Events catering and drinks, airports, docks etc.
Yes, I'm tight and make sure that i'm not exploited by the greedy and unethical.