I have a 2001 Dodge Stratus SE 2.7L V6 Magnum DOHC with just barely over 100k miles on it and it has this nasty squeaking noise coming from the front left of the car behind the tire that started around 96k miles. I took it to a mechanic and he told me that it was the outer tie rod and that it would cost $300 to replace. I looked around and found that the part was $20 plus the re-alignment I would need to do if I replaced it myself. My question is, how can I be sure that it's the tie rod that's bad and if not that, then what is it and how much would it cost to replace.

More info about it, it squeaks when I make left turns, turn the wheel when moving slowly, and when I shift the weight of the car getting in/out of it or coming out of a turn.

Thanks,
Alex