Maybe make a quest to find and repair a machine that give you the ability to buy perks from other classes? Obviously it would be a hard quest, along with the perks being expensive, say, 10K For tier 1 perk, and then adding another 10K farther higher the perk rank you go. Also restrict it so that you can only choose one other class(secondary classes). I think it might be a good goal for others to work towards while waiting for new updates that contain meaty content. Also would appeal to those who like to grind(that is if there are people who exist like that.).