Where did you take it?
Anyone has that has driven a dodge over the past 8 years or so has probably experienced that knocking sound eventually.  When you take it to Dodge they don't even have to inspect it, they know its a hydraulic lifter that has gone bad.  I drive a company truck as my personal vehicle, even so, I still want to make the best decision.   Dodge wanted $6500 to take the engine apart to repair, other small shops won't even do the repair because they typically find more damage then just the lifter.  I asked Dodge how much a new engine was, and the service rep looked like no one had asked him that before.  So he made some calls and said: "Well its lower than I thought, just over $8000."  I ended up swiping the company AMEX for around $8500 to get a brand new engine, 100K warranty, and a new water pump instead of having them tear apart an engine with 125k miles on it. 
For $4300, I would consider a brand new engine with a brand new warranty.  Yes, you would spend thousands more, but you would also spend thousands less by not buying a new car anytime soon.