$3k tops, and only because of the 340. And he'll still need to find someone that likes the 73-74 body-style, and wants to spend more money than it'll ever be worth to fix it.
$15k is delusional. That would be pretty close to the top of the market for a fully restored '73 340 RR.
And now its on eBay...
[ame="http://www.ebay.com/itm/1973-Plymouth-Road-Runner-road-runner-/251428706002?&_trksid=p2056016.l4276"]http://www.ebay.com/itm/1973-Plymouth-Road-Runner-road-runner-/251428706002?&_trksid=p2056016.l4276[/ame]