$500 short, pretty low. There have been reports in the wild of people within $100 (and that might be generous) getting or retaining status. But $500, highly unlikely based on what's reported here in early 2015 (from the 2014 qualification year).
A reasonable valuation of 1k status probably makes it worth spending the $500, especially if you plan international travel next year. Since you're short PQD rather than miles you can use the less time-consuming solution of finding a short expensive flight to get you over the hump, rather than the conventional December search for a long, cheap flight (hello Anchorage, via Houston! which I did this time last year from Minneapolis)