It depends on the situation circulating around that price decrease. From the current bitcoin price then reaching it again to $1, it's a disaster and others can say bitcoin is dead.
So before buying such large amount of coins if ever the price will drop to $1, consider these things:
- Why the price reached that status?
- Why it doesn't established a good support from $400, $300, $200, $100 and $50?
- If it doesn't established a resistance from the stated price then bitcoin is dead.
These are some reasonable investment advices. But still 1BTC for $1 would be very attractive for any bitcoin lover. Who wouldn't want to own 100 BTC by just paying $100? At such a low price Bitcoin will be more of a risky gamble than any form of investment. I would still buy them.