Absolutely it should be opened and used. A lot of collectors never open sealed games / hardware etc as it would either devalue or spoil its perfect condition. I am not one of those people and I've opened quite a few sealed games I've bought so far. They are to be enjoyed and played first and collected second (in my view).
The first 10 copies aside, I think this is priced fairly. Again, this is just my veiw and if people want to pay a premium for the lower serial numbers, that is absolutely their perogative. Also, if those people paying the premium are doing so to help fund further releases then we all benefit at their literal expense.
Saying that, I haven't reserved one as I think I'll hold out for the rom
LOL! You do know this is not really a game, right?