Well part of what happened here is that the people that ran 2 of the planets went inactive. For one thing had my clan mate built the proper defences, Locke wouldn't of been able to make the last drop, which would have prevented the victory for at least a time. Vahalla did do a preety good job controlling the space around the artifact worlds although, which helped lead to such a victory.
As for the tech boom, it did still cost Odin at least 20k to collect them all, which is not easy. However, I do think a increase in price(possibly doubiling) would make such a manuever harder, and make techs more valuble.