I can't say much about the Mongoose, don't have any experience with them, but I think why you're having trouble finding it is because it's a Mongoose Switchback AL (not A2). The L is kind of in cursive and looks a bit like a 2 on the frame. If it's in good shape, fits you well, and he'll sell it for super cheap then it might be worth looking at if you're really concerned about budget and want the cheapest thing that you can get. Otherwise I might go with something better.

The 7.2 FX and Coda Sport are pretty much equal bikes. In my opinion I think the 7.2 FX is the best hybrid bike for the money at that specific price point. That being said, ride both and see which you like the best.
Read this if you haven't yet thesweethome.com/reviews/best-hybrid-commuter-bike/
and this one about locks The Best Bike Lock | The Sweethome