I would say a percentage goes to other projects, probably 5-10%, while the rest is used to pay for everything else that goes into the costs of keeping FFXIV running(all the overhead, plus bringing on more people to do additional items). I could be wrong, but that's what I would hope is the worst case. It could likely be 40% goes to other projects(or even more), but we won't know unless they actually release all the data regarding their budgeting and costs.