you need to look at it this way mate, are you gonna keep the car, or move it on. i mean selling it needing £700 of repairs for an mot you wont get alot for it, would be better of breaking it for parts, but if your intent on keeping it for a few more years to come then its worth it in the long run, but if your just putting in for mot to maybe sell a few months down the line its not worth spending the money