Grinding Gear Games have announced that the private leagues are aimed at two types of Path of Exile players - those who want to compare with their friends with no outside league influence and those who want a challenge, or torture.
Grinding Gear Games stated that the biggest expansion of 2018 will be announced next week as Path of Exile 3.5.0, but they had to announce leagues a bit sooner. Players will get a chance to open their own private leagues now, where they will be able to paly with their friends.
This service doesn't come free though as starting the league will cost 120 microtransaction points or $12. This league will last for 10 days and have 10 player slots, each of which can be further expanded at the price of 60 points or $6. Each added block will allow 10 additional players to join the league or if you're buying time, it will cost the same to prolong the league's existence for 10 days.
Players can also group up and pool their resources in order to start a league, so the costs get divided between them. Same goes for expanding player slots and time left on the league as all of these parts can be crowdfunded on their own.
Now, if players feel like having an additional challenge, they can create a league with additional modifiers that prevent them from buying items from vendors, stop potions from refilling upon entering a town, increase monster stats, remove player resistances and prevent them from using the stash. Those who feel particularly masochistic can turn all of these mods on.
Grinding Gear Games
Players can also base these private leagues on the existing ones, so it inherits the same attributes. Therefore, challenges will also carry over into their private league. The opposite can be done as well, so players can create a league, base it off an existing one and later on integrate it into the parent league. According to Grinding Gear Games, this will not present a fairness issue since the private leagues feature a harder difficulty.
You can read the full post on the official Path of Exile forums.