I`m not that good in those calculations yet. Just begining. At what price you suggest to sell the rest? Should we really wait for 100? 
Here's how I do it:
Say you buy 100 at 65k.
Total buy in, 6,500,000 satoshi
Say you sold half those (50) at 77k
So now your total buy in is 6500k - 3850k = 2650
So your cost per, with 50 left, is 2650k / 50 = 53k
To find out how many you have to sell at what rate to break even, do this:
2650 / (how many of those 50 you'll sell) = Sell price
2650k / 30 = 88.3k
So if you sell 30 at 88k, 100% of your buy in is covered.
Leaves you with 20 GEO left that you didn't have to pay for. I would be very reluctant to sell those at all, maybe just a little here or there if you notice a really nice spike. Save some for 8/23!
Thank you for nice explain
If the the price would drop to 65 again for example that would be good to buy some more, and sell again at peak.