My opinion is that Monsters are too new to be concerned with any "rare" colors or status as collectables. If you plan to ride the beast, you will ruin its collectable status. If you modify it, you ruin its collectable status. In fact, someone has taken a "rare" city and undone all that made the City edition special. Don't worry about rarity. If you like it, buy it. If the mods are stuff you would have done anyway, they have worth. If not, they have no worth (like my # 18 hand painted Splash tank that I think is FUGLY, but someone paid $1800 for).
Opinion #2: That is a nice looking bike that I would be proud to own. But would rather have a stock City for its (relative) practicality.
Doc
BAck from my ride and adding my $.02