Inventory has been low in downtown for some time now. 2013 was when the momentum picked up from a lull and people started buying again, which has been keeping inventory low, especially in highly desirable buildings. As you can guess, in the less than desirable buildings, things have been sitting longer. Various reason for this, which I can go over with you another time.
But the overall effect is that inventory has remained low in downtown and has thus driven prices up. In fact, a couple of my clients with a budget who've had their hearts set on DTLA have been outbid and are now looking into the surrounding areas, which are incidentally on everyone's radar too. Namely, NELA, which covers Highland Park, Mt. Washington, Montecito Heights and others. While it's a Gold Line ride away from downtown, you can get more square footage for the price in NELA. With downtown prices at over $550/sf on average, NELA is still about about $465/sf on average.