Should my wife get rid of her wedding dress from a previous marriage?

This is my first marriage and we've been married for a year. In that time I have sold or threw away everything I ever had while I was in another relationship...I cared so much about many of these things..for example all of my musical equipment and instruments. She considered them tainted from another relationship although my girlfriends never so much as touched any of them. I want to know if I am asking too much of her to get rid of her wedding dress from her last marriage. She says no way! Her only excuse is the fact that it cost so much but I have made many sacrifices to pay bills with my stuff in the past. We are still in a financial jam as I continue to sell everything I care about while that dress is just making me mad. Why is it so important?