Hi Odeysseas,
Which country do you live? there might be one or two FS 650 at the importer here in Portugal.
the 2010 price was € 5740,- (also 2007, ex VAT, IVA, BTW, MwStr) but I guess there's an extra discount possible if still available.
Of course this is for the entire bike, you asked for the engine only but I don't think there's any difference between FS & FE engine.
if you wish I can ask for you.
Cheers,
Adrian