1998 Suzuki Swift Looking for some help on valve problem

Hi I have blown a valve in my car and it is due its mot next month but I have blown a valve and I am looking to see if I can find out roughly how much it is going to cost to have it repaired. Also I was wondering if I could take this part out of an older engine to save some money this is my first car ad dont want to give up hope on it yet thanks!!