The EX you're looking at has relatively low miles for its age, but the following thread has a few common issues that owners here have seen over the years:
It turns out that the electric tilt/telescoping steering adjustment is one of those. I don't believe it's the motor itself that goes bad, but instead it's the plastic gears that end up breaking. It's an issue in other Infinitis and Nissans as well, and I recall seeing estimates of $900 for replacement at the dealer.
It looks like that there are repair kits available for some of those other models with this issue, but I hadn't seen one for the EX. Hopefully this isn't the case, but it's possible you might have to purchase the entire assembly for a lot more money in order to fix the problem.
Nicoclub used to host and share the Factory Service Manuals for the DIYers, but it looks like Nissan had put an end to it. I don't have a copy of the 2008 FSM, but someone else here may have it or could find a workaround.