So three days at your day rate, plus expenses, plus 2 days travel time, which I would charge half rate so that would take it to 4 days. My day rate is $1500, so for me it's $6000 + expenses, which I would book myself. Since others also say it smells of scam, it's most likely a scam. Unless you are a world famous photographer and she has way too much money there is no reason for her to hire you instead of a photographer at the destination. If she is local and you can meet with her to discuss it all and get paid the deposit in cash or EFT after the contract is signed then sure, maybe she does just have too much money, but if she is not local then I would be very wary of dealing with her.
Photography
A place to politely discuss the tools, technique and culture of photography.
This is not a good place to simply share cool photos/videos or promote your own work and projects, but rather a place to discuss photography as an art and post things that would be of interest to other photographers.
Do you think reddit is location specific..do we know where you live and where they are flying you? Is it 24 journey across the world or is it 1 hour flight cross country....what country?!
Jokes aside..you charge whats worth it to you, or whats worth it to your customer..whichever is higher. If in doubt..work out what makes it worth it to you. Time, equipment, business cost, tax, blah blah blah....this is just a business. Like any product, whats the cost of the product, then whats the amount of profit you can or need to take ontop of cost.
Why wouldn't they hire a local photographer? I agree, you should make sure this is a legit business offer first.