Way for thread starter to mark items as Sold

[AtomicTaco]

I browse the For Sale classifieds here, and I think it'd be nice if there was a way to mark the subject as "SOLD". I've seen something similar in other forums; it marks the threads as "Solved".

http://www.vbulletin.org/forum/showthread.php?t=149214

I'm sure the text could be changed to sold instead of solved. While that page states that it is a global mod, I'm sure a simple if statement could fix that.