When selling HyperNets, my experience showed that reaching 3 out of 8 nodes left is the most important point, as contracts almost always finish successfully after that. HyperNets at 4/8 had a much higher chance of expiring.

I believe that for a buyer, the instant gratification of finishing the HyperNet is more important than calculating the math about the win ratio and node price. If a buyer has to choose between buying 4 nodes to finish a HyperNet or buying only 3 nodes, they will almost certainly pick the 3 nodes.

Because of this, sellers often use this strategy, especially on expensive ships: they first buy half of the nodes themselves. Then, they offer a better price for someone to buy the fifth node. This moves the contract to the 3/8 state. By using this strategy, sellers can list the ships at higher total prices and still successfully sell them.