First car nightmare

I bought my first car from the above mentioned branch in September of this year. On the report of the car it mentioned that cv boots were starting to wear so that needed to be replaced. A day later the starter gave in. It is now November and the car has been at my mechanic more times than I have driven it. After trying to sell the car back to them, not only did they make an offer. 2 hours later on a phone call with them, I was told that they can't buy the car back due to the issues. Now how much more money do I spend to get the car up to their standards