There are many flights that pkly between Delhi and Denpasar which would cost you around 9000 INR. Get to the official taxi service close to the airport which will get you to Ubud in an hour at a fixed price around 1500 INR. Then take a bus from Ubud to Kintamani. Make sure to arrive the place one day before the visit because you need to start before sunrise for amazing views. The best option is to hire a bike at Ubud costing you around 300 INR for a day. Don’t fall in trap for guides , one can easily hike along even though the path is marked but it is very obvious. By this you can save lots of money in the process.