The highest I ever paid was ~$510/BTC for about a third of a big one.
Bitcoin is supposed to be for everyone, not just the wealthy, so are you comfortable spending $50 (for example) for less than 0.1btc?
Have you ever paid more than $700/BTC for any amount of Bitcoin?
Yep, I bought all the way up to $1200 in 2013, and then continued to buy all the way back down to $200 by January 2015, and then continued to buy all the way back up to $760 this month.
Bitcoin has a lot of potential and in the long term any price you see now is a good price.
Of course, I'm typically only buying small amounts, and I'm generally using bitcoin all along as well, so the total amount of bitcoin that I have hasn't increased much over the years. I've got an amount that I can feel comfortable with if this whole experiment collapses one day, but enough that I'll be quite happy if it lives up to the potential I see for the future.