In the long run 100% bonus is just bad, it's only good when the tokens or coins get locked up for more than a year.
Then it would be a good thing to give a big bonus, else those investors will dump on the later investors and crash the price..
I too feel there should be some locking system for the 100% bonus buyers. Otherwise the consequences when the token starts trading will be horrific for all the investors.
Another suggestion would be putting a minimum investment barrier for these 100% bonus buyers.