AIBU not to go to hen do?

[Penguin24]

My partner’s cousin is getting married in November and her close friends are arranging her hen do. For context, I have met her a few times at family gatherings but we would never talk otherwise and are not close. I know two other people invited (family members) who I don’t particularly gel with but no issues.
It is going to be two nights and costs £340. That includes some activities but not food or alcohol.
I really don’t want to go. I think it’s too much money for a weekend with people I don’t know well, doing things I wouldn’t choose to do. I know that she would like me to go (she has mentioned to my partner) and I don’t want to disappoint her.
But AIBU to not go?

YANBU. Crazy money for a weekend with someone you're not even v close to

Its nice of them to invite you, but just a thanks but no thanks would do. Just tell them it isn't your thing but you wish them a good weekend. Don't beat around the bush and say you'll let them know, you're thought better of if you are honest.

Say no thank you. I'm sure they won't mind the invite was probably sent to include you, it'd be rude if they didn't ask.
It is a lot of money too.

Often the prices are linked to a certain number going so people can be keen to make people go. I’d just say I was busy, silly money.

God no, I wouldn’t go and wouldn’t hesitate to say No.
I endured a few hen dos when I was younger but these days I don’t pretend and politely decline.

Yanbu. I haven't been to any of my close friends or families hen dos, because they are not my idea of fun. It's an invitation, not a summons as they say!
I'd be very wary of someone you know vaguely being keen for you to go. Run away!

Good grief, I wouldn't go on that kind of expensive hen do even if it were someone close.

I wouldn't go to any hen do for the cousin of my partner that I hadn't formed a close relationship with other than that polite, 'friendly enough when meet at a family occasion' type of level.

Of course YANBU.
Not sure why this is even a question tbh.

Ha no way would I go on that

Ooh no, just decline.

Of course don't go.

That's a lot of money when you are not close with this person. I wouldn't go.

No way! Hate hen dos at the best of times when it’s someone I love dearly!

Oh absolutely not. I’d spend it for a good friend or family member I genuinely got on with, but I can’t imagine many worse weekend trips than a forced fun hen do with people I just about tolerate.