I went through this recently. I tried to get a transit visa, but was denied. I even talked to someone at the New York consulate who told me exactly what to do to get a transit visa.
I ended up getting a business visa. It was a hassle, and quite expensive. I was doing more than a long connection though, as my goal was to visit a friend. I wanted to stay a couple days, and I had been told that if I have a layover of no more than 3 days with Saudia Airlines, I could get the transit visa. My layover was 2.5 days because of the flight schedules.
The Jeddah airport is not a nice place to spend time. It is cramped and rather uncomfortable. Unless the price is a lot cheaper, you might want to consider another itinerary. I can come and go as I please in Saudi Arabia for the next 4+ years, so it wouldn't bother me. I would leave the airport and get a hotel. But if you don't have that option, it won't be quite so nice.