DrugMonkey has a blog post about just how nosy postdocs should be about their advisors' grant funding and lab budgets. (Very nosy, as it turns out.) "Budgeting and grant management are essential parts of postdoctoral training," DrugMonkey writes, noting that while it may feel strange to ask your PI about this, it's actually quite appropriate for people who will have to learn how to manage their own budgets and how much funding they'll need to get a lab off the ground.