Friends?
Avoiding lunatics is one key to sanity and tranquility.

If these are friends worth having, you should trust them enough to be honest with them, and they should be willing to accommodate you.
One thing I’ve learned, over a lifetime of pretending to have more money than I actually do, is that even some of the people I assumed were doing much better than I was were playing the same game. (And you’d be surprised by how many people making six figures are still living paycheck to paycheck.)
Sometimes solutions for problems are obvious and easy. This is obvious and hard.
– Damon Young, "Ask Damon: I can’t afford to hang out with my rich friends" in the Washington Post
Damon Young writes an advice column for the Washington Post. He’s responding to someone seeking his wisdom on the unnecessarily extravagant lifestyle choices of their “friends.” Some of these choices include $200 meals and $500 bottles of wine.
If you’ve earned the capital to cover those expenses, go right ahead and make those choices.
Your money, your life.
If you haven’t earned the capital to cover those expenses, don’t.
The real question is how to handle the situation when your “friends” make those purchases but you... don’t… or can’t.
Young counsels the writer to ask his “friends” to find alternative, less expensive options so he can attend without feeling shame. It’s a great idea and it just might work. There might be a few in the group who quietly worry if they can afford the gathering as well.
The teachings of Epictetus also apply.

This is a prime example of why I embrace Stoicism.
It requires... it demands you ask yourself practical, difficult questions.
I’ve met a ton of people like those “friends” described by the advice seeker. They’re mostly good and decent people. As always, there are one or two apples in the process of advanced decomposition.
Again, there’s nothing wrong with earning capital. There’s nothing wrong with spending earned capital.
The problem isn’t the money.
The problem is in the mind of the advice seeker. Good for them for seeking advice. Good for Damon Young for dispensing it.
If the advice seeker asks his “friends” for more creative and less expensive gathering options, his “friends” will either explore the option or give a dismissive, disdainful reply.
Or something in between.
Or perhaps one or two in this group will privately contact the advice seeker. The group may shrink. This might be the best thing to happen to the advice seeker.
Regardless, the advice seeker will benefit if they possess the courage to ask the question. Because they will know quickly if they are surrounded by lunatics.
There are plenty out there.
Avoiding them is one key to preserving one's sanity and tranquility.