this is atopic that has been covered many times. use the search button located top right next the "15 recent posts" button. type in ball joints as the search keyword and you should find a well of info.
if you are looking to change them yourself i can help. i have changed mine on my 95. if you want prices the mechanics think they are something special and charge as much as an engine rebuild. if you want to knwo what the clatter is going on in th efron end you probably have already found the problem. most recomend replacing upper and lower at the same time. thats up to you. you can buy the parts for $40 a piece for the lower and dismatal the front end and have the joint pressed out or get creative. i used a tractor some have used sledge hammers.
welcome to the site!
