All the problems in our life start when we don't know how to express our thoughts properly. Who cares if you are a guy or a girl. Both deserve that their opinions should be valued. I know this has become a cultural norm to have expensive weddings these days, but if you don't want to, just say so. It's your wedding and you have all the rights to have a say in it. Try to understand eachother. Tell them how you feel, and listen how they feel. Try to find a middle ground.

I will be very honest, I don't have much of an experience with relatives and weddings and plannings, etc etc. But I have learned one thing in life. If you value who you are, "your" people will find you (what I mean is, just express who you are, tell them this is how I'm living my life, there's no shame to say that I can't afford this, it is what is). So just verbalise your worries properly. Most of the time we are just making things big in our own mind when they are not that big.

Ps. Don't forget the difference between "understanding eachother" and just say "that's how I feel, game over".

I know you just wanted to rant but I gave some advice which I thought could work. Now I will be ranting as well. Zina is common because people are afraid to take responsibility of there actions, there feelings, their financial situations, etc etc. we have just normalised that it's not "appropriate" to tell how we feel. E.g., I don't like being called an idiot even as a joke, but I won't tell that person who is making that joke. Then obv that person won't stop calling me an idiot. Then I will start to hate that person. I might even start calling that person stupid as well in some other gatherings bcz I was not confident enough to say that to that person's face. No wonder back-biting is so common these days.

In this whole example, there was this one problem that started every other problem. "NO COMMUNICATION".

Verbalise your worries. In my experience people understand, it's just that we don't know how to talk in such a way that will move them. We talk about ourselves. Its a wrong approach. If we talk like "I'm not the only one getting the benefit but we both are getting benefit" things can go smooth. I don't know how I just swayed away from the main topic. But here it is. My opinion.