Definitely get one from a wrecked car.

They are super $$$ from the dealer, and a no-name brand will run you at least $100, and it probably wont last as long anyway.

Mileage isnt too big of a deal, the lower the better obviously, but ask people with 150k on the Integras if theyve ever replaced that part...you may get it with 80k on it for $30, but if it lasts another 80k without a problem, no biggie.