thoughts?? opinions?? please?? i beg.
This is a tough situation, and you're not wrong for feeling stressed.
First of all, what the fuck. Two months notice for a destination wedding is retarded.
I think your bf is in a much easier position to say no, you're not married so his relationship to the bride is tangential at best. Lucky him.
You say she's your best friend. Are you in the wedding party as a bridesmaid or something similar? If not, are you
sure she's a bestie?
If you don't go, you're going to feel badly about it. Accept that, and don't let the risk of feeling badly affect your decision making.
It sounds more like the issue is financing this trip, and the sentiment of being jerked around. Financing the trip isn't something she should help you with, and honestly, it's not her problem. It is a genuine problem for you though, and it is a justifiable reason for turning down an invitation without causing any hard feelings.
Being jerked around is something she could've helped you with, and while you can't use it as an explanation for not going, if she's not completely retarded she'll understand how her actions might have made friends less enthused about sacrificing time and funds to attend her day. If you want people to be there for you, don't make it hard for them to do so.
Keep in mind that if the planning is this shoddy, the day of may be equally clusterfucked. Weddings are supposed to be fun, but if you end up being pulled in to assist with event bullshit, or you have to deal with the lack of event planning, you're going to
really resent the money and time you put out for this.
I have no idea what sort of wedding it is, but if they don't know the numbers 60 days out, how the fuck are they organising food and tables and chairs? Is it going to be a mess of too many people and too little food and drinks? Or are there only going to be a few people attending the reception and you have to make awkward conversation with her weird drunk uncle the whole night?
Friendship is more than a single day. If you can't attend for good reason, a real friendship will endure. And if it can't endure, you were just as well not going anyway.