I should have mentioned I don't really have a FIRE goal. Work in a relatively low income field and am too lazy for side hustles. I want to be debt free (eventually?!), have some cash savings, save 25% in my 401k, not spend money on eating out/shopping. Credit utiliization is still quite low; I have probably $10,000 available to me on different cards, so I'm using around 20% right now. Most of the debt will be gone by december...I think the real challenge is not to just do this cycle forever, where in Christmas I am buying gifts (not many, and on a budget, but still) and traveling to see family and continue to put the extra spending on 0% cards. Then again, christmas does come with a bonus and often with gift money, so it could also be quite easy to make enough progress then that I move to building an EF.
It all comes back to whether I'm going to be on an endless merry-go-round of carrying a low-grade 0% balance and then the question of whether, given that it's 0%, it matters. But that feels like a potential slippery slope. Right now 20% goes into my 401k (including a 6% match). That's the sum total. I take home roughly $1650 each month: $600 to rent, $600 to debt service (again, no interest, but still), $50 to my cell phone, $30~ to charity, $333~ to food/alcohol of all types, around $33 to utilities.