I think as long as they realize not all family can come that's fine if it's what they want. I do feel though that if they know IMMEDIATE family can not afford to go, they should either reconsider or pay for them (Mom, Dad, grandparents, siblings)..........and I know that won't be a popular view, but if I wanted a destination wedding and one of my family couldn't go only because of finances (truly, not just didn't want to), that's what I'd do.
My brother was married in a very formal evening wedding with a very formal reception with no children allowed.
My dh's sister was married in her brother in law's home, wearing a simple dress and presided over by a preacher in her new family. No reception.
My dh's brother had a country club wedding, that really was more down to earth than formal, despite the setting.
Dh's other brother was married in a traditional Blackfoot ceremony. Very fun. No reception, but a party afterwards.
We had a church wedding, quite traditional. Our reception was in the church's reception hall, all done by my mother and I. We made fruit kabobs and stuck them in purple cabbages, had a cheese and cracker tray, had bought little clay cupids to sit in around. No alcohol was allowed, which was fine with me. I had a flower topper on my cake which was beautiful, and my bouquet was my fave flower: daisies. The flower lady tried to talk me out of it and into roses, but I wouldn't budge and I'm so glad for it. I did the centerpieces on the tables: baskets of traditional Mexican candy with traditional Mexican paper flowers entwined on the handles........all made by me. We had a chocolate groom's cake completely done for dh by me........with chocolate iron chains and balls on it, and wedding rings encircling it and spelling out "Chains of Love" in icing. After the reception, which I did open my presents at as my aunts and grandmas love to see and talk about gifts, we had a party at our house. The reception was for dh and I to celebrate our new married life with our family. The party was more for our friends.
Each of us: Me, DH, Dh's brothers and sister and in-laws, and my brother and sis in law..........each of us feel as if we had the most perfect wedding. That's what's important, I think, whether it's in Hawaii, Roanoke, Oklahoma City or Hoboken.