Advice about having a crown on a tooth

I had a check up yesterday 21st September. To my surprise and shock l was told by the dentist that one of my front teeth which is nearly all filling would benefit from having it crowned . £300! I've never had any problems with this tooth. Although I've made the appointments to have the work done I'm not at all happy about it and apart from anything else l didn't like the way in which l was treated and spoken to. As if that amount of money would be no problem to find!
Advice from those of you who have crowns please should l go ahead or leave it well alone until such time as it really needs to be dealt with. Thank you