The FAA-recommended housing options have to comply with several requirements, such as not requiring a lease or deposit, and allowing a no-fee moveout with zero days notice and a full refund for unused days. Obviously no one is going out to OKC planning to fail, but the sad truth is that it does happen - and being forced to pay a few extra months for a unit you're no longer living in would eliminate any potential savings. Even if you don't fail out, a circumstance like another government shutdown could screw you. Students aren't paid per diem during the furlough, and while all the FAA housing providers did not charge students during that time as a result, an unassociated location may not be so generous.
If you're at a FAA-recommended location, Student Services will also go to bat for you if you ever have issues with your housing - I know of someone who was having trouble getting maintenance done where he was staying, and Student Services got involved directly and made sure the work was done and allowed him to focus on his studies.
Many of the more popular places also have FAA-provided shuttle service to and from the center, which relieves you from having to drive and prevents you from being fired if you're ever late to work. On your first day they'll drill into you that if there's a huge accident or other delay and the shuttle is 30 minutes late to class, you're totally in the clear. But if you're in your personal vehicle sitting directly behind the shuttle stuck in traffic, even if you actually walk in before the shuttle students, you can be fired. There's also the less tangible benefits of camaraderie and study sessions with your classmates, which are vitally important in OKC especially in Enroute.
Personally, I looked at finding my own place like you've said, and it just didn't seem worth the hassle and risk. I ended up staying at Isola Bella at a decent rate, which while not quite as cheap as Kim's, still left me pocketing $15ish per day in housing per-diem. They also provide two hot meals a day, which meant that I was actually coming out way ahead when you consider that I spent almost nothing on food and groceries. I know there are lots of negative reviews about IB on here, but I personally had zero issues and I'd definitely stay there again. It definitely wasn't as modern and nice as Anatole, but the cost saving and food more than made up the difference for me. And just to be clear, I'm not being paid or compensated for saying this - just my personal, unsolicited opinion.
