Friends did not invite us on vacation

Just trying to check my feelings here. My husband and I have been close friends with another family for over 10 years. Mom and I have become best friends, husbands get along, and our kids are also close. Her husband is quite wealthy and we are normal upper middle class. Money never was an issue in the friendship. Social outings used to be manageable financially. A few years ago we met two other couples, and my best friend and I hit it off with both moms and now we all regularly hang out. Her husband in particular really likes those husbands, as they all work in the financial sector. Slowly, social outings became more expensive, and often we had to say no to dinner invites, etc. Over time I have felt like her husband is indifferent towards us. I get it, there are new friends in the mix, giving him attention and they have the financial means to go to nicer places. Despite this, my best friend always made every effort to include us in invites. Recently, I learned they all booked a trip to Las Vegas, just the adults, and we weren’t included in the planning. They picked the priciest hotel on the strip and made dinner reservations each night at fantastic spots. My best friend is close enough with me to know it was highly unlikely that we could afford it, but am I wrong to feel slighted to not have been included at all in planning? It felt like a gut punch when we were out one day and they started to talk about it in front of me. I know the invite would have been a symbolic one, but even a “I know you probably can’t swing it, but here are the details just in case” would have been nice. Am I being too sensitive here?