They gathered resources from nodes with focus and hold it.
They do leveling for life skills with unfocused gathering.
Accounts with full 20 lvls is not cheap at all.
After they hold enough resources - they do a massive crafting campain and sell crafted items with minimum price to collapse economy and nobody in the game can sell items lower than lowest fixed price.
After some time amount, when most of resources will be sold - bot owners sell accounts with billiards of unbound luno.
Its the same strategy as in any mmo