Fix broken MacBook lcd screen – or buy new?

I was a complete idiot and threw my charger onto my desk and it unfourtunatly smacked into my computer screen. It made a huge crack and now around the crack is weird flashing ranbow stripes and big black and white spoltches. I want to get it repaired, so going to an apple store and getting a new screen put in but i wanted to know how much it would cost and would it be more worthwhile just getting a new computer? thanks!