Especially since puzzle 71 is very close to being found and it has over 7 BTC in it.
What makes you think that? All the clues lead to the exact opposite conclusion.
Even if someone makes a totally fair pool and the entire planet joins it and gets a fair share of the prize, absolutely everyone loses half or more than their investment. With that in mind, how would the puzzle be "close to being found", unless a shitload of people (and I mean a LOT of people, not a couple of thousands) are scanning randomly, and some dude gets lucky by pure chance? It can only happen, with very high chances, only if everyone drops everything and starts dedicating all their time to this.
You can make the range more smaller in some way, scaning all the range or going random is not the best solution here. This is just my opinion, when I will find it I will let you know ahahaha