The price premium applies to all champagne though. Even the cheapest ones (eg the one at Aldi) start from $30, while basically indistinguishable if not superior prosecco/cava/sparkling can be had for $10.

Putting a good $15 bottle on the table doesn't tell your friends "I really want to celebrate this. It's a special occasion to me". The $35 champagne that might inded be worse, does. Especially if you are the kind that often drinks the $15 ones!

And that's imho the selling point of (at least the lower end) champagne. I still do that occasionally. A $20 difference is a pretty small price for a "signal". It's not stupid just because the content is indistinguishable. I pay for the label - because the label is the effect! It's the product!

That's also why such producers need to be careful with others using their name. They are selling a name while everyone else is selling wine.

I must be in a casual social circle because a popping a 5 bottle of bubbly is just as celebratory. The idea of getting out “the good alcohol” for a special occasion is so foreign to me.

"Trois-Rivières" does sound French, but it also totally sounds "rum", not wine ;)