When I sold off the colonies out of my 90 most of them sold for $100 or less. Looking back, I should have fragged them and made more money, but I didn't have the heart to hack them up.
I had some really sweet pieces. If you get the right person walking by that really wants that coral you'll get the price, but those chances are slim - especially when it's browned out. Personally, I would never buy a colony because the growth pattern will change when it's moved to a new tank and it will look funny.