How much you need to have time to make a fake video, high quality (two days / week / month?)
And How much it costs

(For example, two minutes in (length video contains explosives and gunfire how take time)

Why and what are you trying to 'fake' or do you mean that you want to make a movie/short film?

This is a question that doesn't have a straight answer because there are too many variables. Costs include equipment, crew, cast, special effects, licensing, permits, etc. Those costs depend on where and when the video is being produced.