I have seen some on eBay with an engraving on it and that have sold. they were around the $200 price point though. There were some that were around the $250 but didn't end up selling and lowering the price. Although I did see one that sold for around $265 but it was brand new and the colors were also customized.
So if your friend is really keen on selling it, the $200 price point will do him good but it is a little on the cheap side. He can always have it at around $250 and hope for the best.
EDIT: Or like elpeterson said - swappa might give him the most money.
In any case, I hope that he gets a deal that he can walk away happy with.
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