Do call up Kaspa or ADL in wairau for a second opinion. Honest crowds that have realistic pricing. It could just need "A flush and a filter" dare I say it...
Sounds like a Legacy or Outback 2.5. Do not cut your losses just yet, If it is a subi they are good cars! Please do not go deceiving someone selling a broken car, state what you have if it is indeed the case.
Evaluate when all the next service items are due, Brakes, Tires, CV joints, bushings, balljoints and if you feel the car is still good for another 25,000KM on the current running gear I would repair it and keep it going. If you require service items to be replaced soon get rid of it. Trade it in to be honest, Make it a dealers issue.