I'm not an expert but I keep up with what the vintage dealers advertise nationally. The range would be from about $850 for a dinged refin with some replacement parts or "upgrades" in a mediocre non-original case, to about $5000 for a complete original, with hang tags, in excellent condition in an OHSC. Maybe more if it has an impressive provenance. So maybe your friend's is in the $2800 to $3200 range?
Yer friend has to have it appraised by an expert to confirm the condition if he's lookin to set top dollar price in a truly honest way.
Cheers,
