AITA for not wanting to go to my BIL’s destination wedding?

My husband’s brother is getting married overseas in 5 months and we looked at the flight and lodging costs and just can’t afford it. Hell, even if we had the money we probably still won’t go since it’s a LOT of money to spend for only a few days and we have a mortgage with very high interest rates. The bride and groom themselves specified in their invitations that they’d understand if people can’t go because it is quite an expense since it’s not all inclusive and the guests will literally have to pay for everything other than probably the wedding dinner.

My parents-in-laws are obviously going and have already decided they’d also pay for flights and lodging for their other son and his child because they wouldn’t be able to go otherwise.

When we told my parents-in-laws we weren’t going, they offered to pay for us as well. Now, my MIL and FIL are not exactly well off and are only a few years off retirement. They just have their little life savings and based on the estimates, will probably already need to spend around $10k+ for just the 4 of them. My husband and I don’t really want to add to their financial burden. We don’t begrudge the other brother for getting his expenses all paid for since he does really struggle as a single dad and him and his little son deserve a decent holiday. For me and my husband though, we’re just happy to celebrate the wedding on Zoom.

Of course, our parents-in-laws didn’t take this news lightly and would constantly message/ring us in order to guilt trip us into going since it would really upset them if we don’t. While talking to my MIL the other day, we accidentally found out that the bride and groom called us ungrateful for refusing the offer which really upset my husband.

AITA for not wanting to go to my BIL’s destination wedding and declining my MIL/FIL’s offer to pay for us?