So in OSRS if you finish a certain diary, a NPC gathers battlestaffs for you to go and collect. Since we do not have any diaries there should be a simulator used with GP. For a slight example, Blast Furnace, with GP you get time to use that for xp. The simulator should be a certain amount of battlestaffs gathered overtime, and the more money you put into this the longer the battlestaffs will be spawned that you can collect after the time is up.
I get why you say this.... As an EIM it is a pain in the butt to get 99 crafting. You literally have to use any crafting supply you could possibly collect in order to reach that goal. There is already a few things in-game such as Vorkath, magic stall for thieving bstaffs, as well as getting them as noted drops from skeletal wyverns. If anything I would expect to hear someone complain about a lack of orbs in the game. I would love to see a way to make molten glass that you could then turn into uncharged orbs so that you could make bstaffs in a similar manner to osrs, and this would give EIM a more reliable method to train their crafting. If you need help with crafting ideas or something of the sort, then please just hit me up in-game and I'll share all I know.