hmm,,I've done a fair # of TC's over the years,,never bothered with OEM's,,,never had an 'issue' for that.
....perhaps I've been lucky,,but it's a 3-4 hour job for moderate skills and knowledge,so long as you've got a mechanic's book.
.....and what a huge difference in engine power you'll notice if your current one is 'rattling'!!!

...$100-120 sounds right!