AITA for delaying the booking of a trip, and causing airfares to go up due to that.

Hi,

I (18M) was involved in the planning for a holiday to go to Europe in December of this year with my girlfriends family, which includes her, her mother and my best friend. My girlfriend and my best friend both obviously really wanted me to go, so I was invited. When I was invited, it was around May of this year. I tried to encourage the planning process by asking everyone to sit down and discuss the trip (as it’s a long, complex international trip) but nothing came of it. I kept asking, as I needed to get some form of budget for my mum. I was unable to afford the trip by myself of course, as I am 18 and work a part time job and didn’t have that long to save. I was unable to get that budget, despite my asking, as my girlfriends mum just wouldn’t sit down with us and try to book it. Because of this, I was doubtful the trip would go ahead, however I still went out and got my passport. As the months went by, and it got closer to December, I kept asking again and again for a budget, as my mum needed one in order to organise her finances. When it got to October, my Girlfriend’s mum kinda freaked out and realised she needed to book immediately, and gave me a deadline of one day to pay for everything. I did not meet this deadline. I could pay for the airfares, but since there was no budget still for the accommodation while in Europe, my mum was hesitant. The length of the holiday was extremely long, which wasn’t communicated to me, and I was still unable to get a budget and was told to just calculate the average room price. I communicated that I would be unable to afford it, and was trying to figure something out so that I could go with my mum, who was away internationally for work. Then, my girlfriends mum realised that it was too expensive, and then shortened the holiday significantly, without telling me. She then told me I would have to contact the travel agent myself to tell her if I could come, because apparently everything was booked. My girlfriend and my best friend, still really wanting me to come tried to use their inheritance money to pay for me, so that me and my mum could pay it back. I then contacted the travel agent and told her I could come, and she said that was no issue and that nothing was booked. Although I really wanted to come, I was uncomfortable with borrowing money from my friend and girlfriend, so I understand why my girlfiriends mum was completely against it, and thus that didn’t go ahead. During all of this time that I was trying to figure out if I could come, which was around 3-5 days post deadline, the airfares went up significantly as it was very close to December, and now my girlfriends mum is upset with me, and is trying to ban me from housesitting for them while they’re away. My best friend and girlfriend are on my side, but their mother doesn’t want to talk to them and is just ignoring them basically. I feel bad that the prices went up, but I feel like it’s not my fault as I tried to book earlier.