Is it bad of me not to go to my brother stag party in Vegas?

Go for it mate. It's your brother and you only live once. If I was you I would get involved and help them to plan things a bit. I bet you there is definitely some way how to save some money. Where is will there is also solution...

I think it would be totally okay to skip out on a stag party that would cost that much to do especially if you can't afford something like that. However, if you two are the type to do things together you should do something that's just you and him when he gets back. Another option would be to contact the guys who told you about the party to see if they can't do something more local instead or be willing to have another party when they get back to include you.

I don't know. I am all for supporting and celebrating with a family member. It's kind of cool to travel to new places to explore. Vegas has a reputation which is kind of cool. There are things to do here that has nothing to do with gambling, strippers and etc. but....it sounds super expensive for you. If nothing is planned and all they're going to do is get drunk, visit strippers and wander Vegas, it doesn't sound like much fun. If you do end up coming and want suggestions of things to do besides drinking, gambling, and strippers, I can give you suggestions.

Vegas sucks if you aren't into spending your money on prostitutes and casino games.