It's got over 100k, which automatically means a lot of people will sack it off since there is a general feeling that over that mileage is a crazy gamble for some reason... plus, it might need a few things doing to it which could mount up; front end spray? tyres?
You're right though, a manual Imola E46 M3 is a rare sight and if I was local then at that price I'd be tempted to go along, take a gander at it and see what sort of movement there might be in the price.
Cheers,
Grant