The value of bitcoin has been fluctuating between $530-$760 within the past two months. Investing at any more than $650 per Bitcoin is not a great investment. While I disagree with you that Bitcoin will fall, the purchases of mining hardware have been off the charts and buy orders for BTC are increasing. While BTC may be a bubble at times, it has a stable ratio.
BTC has been fluctutatin between 500-750$ for 2months but it doesn't mean it can't break the upward resistance!
Inflation of the USD, new investors and new bitcoin enthousiats, adoption by a few major companies could bring us way higher than 750$