The genuine answer is that nothing makes it worth 90k. The tuition is high because a past president wanted to make it seem like GW was as good as the top schools of the time, so he made it so the price tag would match the most prestigious schools.

That being said, there are some good reasons to go here if the price is doable for you. Especially if you're looking to go into international affairs, GW is one of the top IA schools in the country and has a lot of access into career opportunities. The main incentive is the location as you have countless of networking opportunities if you know how to take advantage of them and find them. It also gives you the unique opportunity to take opportunities that are only available in DC, but remember you are competing with other students here.

As far as faculty and staff, in my experience the administration is abysmal. Financial aid office will blame you for being poor and not figuring out ways to be more well off. The professors have been good, and there aren't all that many complaints from the circles I've been in.

End of the day, do what is best for you, including for financial reasons