BIL asked us to attend a destination wedding

My partner and I got engaged in June, we have been dating for over 5 years and been planning on getting married for a few years. About a week later, his brother proposed to his Gf in Italy. They are a bit younger than us (we’re mid-late 20s they’re early 20s) It was very cute, and we were all happy for each other.

While wedding planning we have had to shift our plans around a bit, since we all got engaged around the same time the wedding times are going to be similar. We have been planning around them to avoid getting married at the same time to give a little bit of a break to our parents and so everyone gets their special moment. They were planning a local wedding since their families are from the same town (NY, US).

We were helping and talking about it a lot and then all of a sudden they dropped a bombshell. They decided that their wedding could be done for a lot cheaper in Italy, and they are making the wedding party small, just family, and want us to fly out to be with them. SIL extended family is from italy but all of us live in the US. We are all very poor and can barely scrape up the money for our wedding and my parents are helping me pay a bit which we appreciate a ton. However, my parents said if we can afford to attend Italy, we do not need their help paying for our wedding.

My partner kind of wants to go since it is his only brother, but we are drowning in over $100k of debt (mostly his student loans) and are trying to get married ourselves. We’ve agreed to not go, and told them so, but it’s been tough and created a lot of family drama. Their parents can’t afford to go unless they sell a lot of their stuff. Is it normal to have destination weddings like this and invite people you know can’t afford it? They are 100% aware of our finances. Would we be jerks for not going?

Edit: Thank you to those who responded! I tried to respond to comments asking questions and ones that had ideas we hadn’t thought about. Also removed extra details that were not relevant.