Tough call, I'm not sure what a really clean W124 is worth these days. It looks to me like it needs about $3K worth of cosmetic stuff and I'm assuming the oil leak means it needs a head gasket (about $1K, I think). No offense, but I would also reinstall the correct air filter assembly before trying to sell it. I guess I would take the top price for a $300K W124 and subtract about $4K