I find it strange that they are out-bidding each other like this when there are over 8 days left. I am not too experienced with bidding, but I thought that the normal strategy was to maybe place a placeholder bid if there is no activity, but more generally one waits until the last second to set a reasonably high bid. Going on a 1v1 with fast out-bidding over a week early seems bad for everyone except the seller. Perhaps someone can explain.
Relevant to note that every other bid comes from the same bidder, j_s_0e6b87. Here's what I'm guessing about them:
They likely know about Hexbear, since they were bidding on the address right off the bat.
They aren't a domain squatter. A domain squatter would try to minimise the amount of money spent on a domain; and yet they're bidding too early, too frequently, and values considerably higher than the necessary to be the top bidder.
They aren't using automated tools, since the the times and values between the others' bids and theirs are too erratic.
Either they don't plan to actually win the bid, OR they have lots of money (to the point that US$710 is pocket change for them) and really, really bad blood against Hexbear.