Should My Parents Renew Their Vows At My Wedding?

My parents gave my fiance and I a strict budget, but then insisted on us having the wedding in my home town where they still live (which is more expensive than where he and I live) and inviting some of their friends I haven`t seen in several years. My parents asked us if we would push our wedding back a year they could do their vow renewal at our ceremony instead of having two separate events. They said the new budget would be more than double the original. I agreed at first mostly because I was stressed about working all these people into our original budget, and they said it would be very simple and after the ceremony it would be all my day again. Now my parents are taking dance lessons (my fiance and I can`t afford them), my mom wants to walk down the aisle in a formal cream colored dress with a bouquet and have a dance for the two of them at the reception. I feel like they are trying to overshadow my wedding. I don`t want to take back my word, but is it selfish of me to remind them that they already had their wedding and this should be my day?