imo you are comparing apples to oranges by mentioning the .org sale. In fact its not exactly valid to say it sold for 5 figures (if you use £, it wasn't 5 figures).
It sold in 2008 - exact match benefit was flying high, people weren't getting penalised all over the place, Google wasn't bending over backwards to rank brands, pandas and penguins were something you seen at a zoo, & google weren't stuffing the serps with their own ads like this -
https://www.google.co.uk/search?sit...8.10.0....0...1c.1.32.hp..2.8.839.S2eL1ezZhrg
I don't see it being worth much really - look at the top results... you can't rank it and you can't build a brand on it with that extension. So what exactly are you going to use it for?