Have the rear main seal checked for leaks, because if the flame trap looks bad and the "jiggle test" fails, it may be leaking and can be a somewhat expensive repair. What type of uneven wear on the tires? Inside edge, middle, or outside edge, and which of those on which tires? The car may just need an alignment, and since the interior sounds a bit worn, the previous owner may not have bothered with minor things like alignments (not so minor to most of us). Does the car drift or pull to either side if you take your hands off the steering wheel? How about when braking? $6200 is way too high. I think $3500-$4500 is a good range to shoot for.

Good luck.