Bitcoin price doubles about three times a year on average, and will keep going up at this rate until the final growth slowdownWish I had Bitcoins in 2009...
I urge you to invest whatever more you think is prudent NOW.
You can ask Bitchick, we have invested as much as we can afford to lose (and probably a little more than she is comfortable with).
You both are so fortunate to completely share this amazing adventure.
When I performed parameter sensitivity analysis on the hand-fitted logistic model, I found that the rate of logarithmic growth is the about the same regardless of the value of the maximum-bitcoin-price parameter. So no matter where it ends up maxing out, the price will get there doubling about three times a year on average.
I know. I was the one that asked somebody to do it to begin with because I was busy that weekend.

This "amazing adventure" feels as stressful as watching a suspenseful movie sometimes. (Although I watch them with BitChicksHusband I often have to leave the room because I get so stressed out watching them!)
That said, I am still thankful we are involved. Better late then never. And I have come to realize that the amount of coins we have might be irrelevant depending on when we decide to use them (with the price doubling at three times a year) Many of the earlier adopters are using them to purchase expensive cars right now and may be left with the same amount, or less coins than we have if they spend most of them. Of course, the smart ones will make sure to hold a sizable amount for a long time.