In general, I try to avoid buying parts from the discount places (Autozone/Advance). Pay a bit more (in some cases, a good deal more) and get something you know has a good chance of being reliable for the long-term from someone who specializes in European car parts. I can't speak specifically about the steering rack, but I do know of LOTS of people who have had problems with rebuilt components from the discount places. Their rebuilders are clearly focused on quantity and cost, rather than quality.

The last rebuilt component I personally bought from one of the discount stores was a starter for my A2 Jetta (bought it from Autozone). From the start, it would sometimes start the car fine, but other times it would crank slowly. Within less than 100 miles, it started sporadically failing to stop spinning, so I would be driving down the road with the starter motor spinning, even though the gear was not engaged with the flywheel.

Spend more up front, and do the job once. Or spend less and run a big risk of repeating the job.