To invite or not

I’m having some difficulty in deciding to invite my Mom’s extended family to the wedding. For the past year my mom and one of her brothers have been feuding, this is not the first feud. It also directly involves my uncle’s wife, one of my cousins and her husband and my grandmother. They have not spoken to my mom or dad in a year. My uncle was in the wrong and told my sister he apologized first during the last feud and will not apologize first this time. They have not invited my parents to christmas, i got a “happy birthday” but not card, no calls or messages. They have invited my sister and I to christmas ans i feel like it is only to upset my mother. I do not think kindly of my Aunt, Uncle or cousin and her husband. My opinion of the situation is that they did something very wrong. I’m conflicted in whether i should invite them to my wedding or not. My mother says she doesn’t mind either way but i just feel like i don’t want to pay for someone to be there if u am unhappy with them. I do still want to invite my mom’s other brother, he lives across country and i only see him once every 5-10 years. My fiance is only inviting one aunt and a few cousins as well. What are your thoughts? I said to myself and my fiance that i would give it until christmas and they still haven’t resolved it from last February.