A deck is usually ₹3–6L, a site ₹6–12L, an identity more. We quote a fixed price against a fixed scope after one conversation, and we will tell you if your budget does not fit before you spend time on it.
Two to four weeks for a deck, four to eight for a site, six to ten for an identity. The first week is writing, so there is nothing to look at until week two. That is deliberate.
Often. We can hand over a system your designers run themselves, or sit inside your team for a quarter. What we will not do is produce files nobody can edit after we leave.
That is a normal engagement. Most relationships start with one thing that has a date attached.