Value would probably depend on a few things. I know these aren't cheap but if you're into beep and dig machines they're pretty good.
What coils? It looks like the one on it is the 10" DD. Do you know if it's the 10 or 18 kHz?
Did your friend purchase new and if so, when?
What's the overall condition?
I'd be interested if you would ever want to sell/trade.