$100m/yr for office costs are high, assuming these bills are actually being paid everywhere. They've been evicted from their Colorado office and have been sued for not paying rent at a SF office,[0]
Either way, it pales in comparison to the $300m/qtr they're on the hook for for interest payments to banks that financed $13bn of the deal.
[0]https://globalnews.ca/news/9385713/twitter-overdue-rent-san-...