The highest I ever paid for BTC was 8 USD
The lowest, 0.7 USD
I bought 150 BTC this week, and sold shares on GLBSE for some more BTC. Later (after GLBSE withdraw get fixed) I will use those shares on bitcoinica to buy even more BTC
Actually, I lost lots of BTC when it went from 2 to upward (I was daytrading, sold all my BTC at 2, and it jumped to 4 before I could buy it back
), so if BTC drop back to 2, I will buy craploads of BTC...
But I am not seeing that happening, so I am happy to buy BTC now