Where is the cheapest and most expensive place in the world to by champagne?!
Answers: I would assume the champagne region in France is the cheapest.
Generally the cheapest place to buy Champagne is in Champagne from the winery and the most expensive places will be somewhere that taxes it heavily.
The tax on wines in France is virtually non-existant, but in the UK (which has Europes highest alcohol tax) Champagne is taxed 3 times, there is duty, a sparkling wine tax and then there is 17.5% VAT applied on the price AND the other two taxes. But because the UK is the biggest importer of Champagne, and thus buys in vast quantities, there are some bargains with Champagne, such as Lanson Black Label for 10 pounds.
So, I'd go for Champagne as the cheapest and like Thailand (which has very high import tax and alcohol tax) as the most expensive)
your home on the internet for both
Since champagne only come from Champagne, France. That's your answer for both questions.
Purchasing it online will only jack the price up higher because of importing costs.