I don't think there's a clear right and wrong here. If it were me though, I would spend the extra and bring someone really close to me along. I think you have more skin in the game and just paying the extra is less of a loss than letting the whole thing go.
This is easy. Here's my take.
1. I'd make your aunt pay for the $750. It's a contract she signed up for from the beginning and she should commit to it until it's paid. If she won't budge, let it go. Things happen and it is what it is.
2. Take the trip. Why lose theopportunity of a lifetime over someone else's situation. You may never have another oppotunity to take that cruise. Do it while you are still young. I travel 2-3 x/yr and come home with memories that will last a lifetime and can never be replaced. Never reschedule. Most likely, it'll never happen again and you will regret it.
3. Take your friend. Is she willing to take a deal like paying just the airfare? Maybe in installment payment? Or pay just half of the fare? She's already saving $1,200 for the cruise. If she wont budge, find another friend who might be willing to make a little compromise and pay just a portion. If no one else, and if you're willing to pay for your friend for the entire trip, go for it. Make sure you do it because you want to and never bring it up again in the future when you ask something from her and she says NO. Money is tangible. Friendship will last a lifetime. Don't lose your friend over money.
4. Finally, go on the trip. And have an amazing time !!!
This is a tough one so I would put my energy towards what you can control:
1 - Having your aunt cancel, I feel, is understandable as the timing was beyond her control. I would not ask her for the remaining balance (however, if I was the aunt, I would pay YOU back at some point.)
2 - I understand families and in my opinion (which you asked for ) is at 30, your father needs to respect your choices. This can be done without being disrepectful to him. You have spent a year planning this and have paid for it. If he 'refuses' to let you go and you agree to allow him that power, he should reimburse you for the cruise. This could be an amazing trip for you and if you WANT to do it on your own, go for it.
3 - If its a really good friend who wants to come with you and cant afford it, work something out money-wise. If this is not someone you really want with you, then go solo.
You are now less than 30 days out. Getting a new guest with a passport will be hard but you could try. I suggest try 2 different options a) try to find replacement at any price and aunt pays for anything that party can't b) push back the date and aunt pays for any fees c) I understand she does not want to go but that does not revieve her of the debt. If she can't pay then you go by your self and her birthday and Christmas for the rest of of life were the trip she cancelled.
Tough one. If it were me...
I would congratulation the aunt on her custody win! I'd tell her how happy I am for her and her son.
I would tell the aunt you understand why she won't be going on the cruise and that you will miss her.
I would remind the aunt that she made a committment and you were counting on/need the funds she promised you.
I would let the aunt know that I was scrambling to find someone to take her place.
I would let the aunt know that if I found someone who would go and would pay for part or all of the cruise, that you would reimburse the aunt ALL funds received from the other person.
Hopefully your relationship with the aunt is filled with love and respect for each other. Enough that she would honor her financial committment and pay you. Enough that she would trust you to try really hard to get someone to pay for part or all of the cruise and reimburse the aunt any funds owed.
Some excellent answers...
Yes, your Aunt SHOULD pay you back, but if she doesn't, don't lose your Aunt over it... she didn't plan it and these things happen.
Pay your friends air fare if you're able to and take her with you.