How much money would in need for this trip?

I'm planning a trip soon to Cali. I was wondering how much money would it be right to take on my trip? I'm planning to go with someone and I would like to know how much would I spend if I do the same things that I do in NYC? For example go to the movies, public transportation, food at a restaurant, food shopping at a super market, bowling, bar. If I go to a barber shop how much a regular haircut cost, and if I take my girlfriend to the salon to do her hair and nails how much would it cost to do all that. And also are clothing very expensive? P.S I know Cali could be expensive if I want to live like I live in NYC I just want to know how much money do I need for two people to stay for 3 weeks? I'm staying in my friend's house she lives in La Nueva Base she is currently in NYC but she let us stay at her place.How much money would in need for this trip?
I always believe that you'll spend a bit more because you are on holiday.



I start by comparing the cost of living. I don't live in the USA but to me, there doesn't seem to be much difference between NYC and California.



So you end up spending what it would cost you for three weeks at home, plus a bit more because you are on holiday.



Work out the cost of 4 to 5 weeks in NYC and you have your answer.