I just went through this very same search.
A couple things I learned about buying a used stock Mopar TJ soft top is that depending on the year of your jeep, you ideally need to find a top from either 1997-2001 or 2002-2006 due to some small design changes. This affected both the bows and the windows, so not everything is interchangeable. Also, while Bestop might make the stock soft top, the Mopar bows are a better quality than what Bestop has to offer. This is according to several side by side comparisons of people on this forum.
FWIW, two weeks ago on CL I was able to find a barely used 2006 Mopar top for $270, complete with bows, tinted windows and all hardware (minus the 4 attachment screws).