This is a common question in the AU forum. For what it’s worth, Money Magazine says AU is the 456th best college for your money in 2019. http://money.com/money/best-colleges/profile/american-university/
That’s a question each person should ask about each college in consideration
204 in Kiplinger's Best College Values 2019 https://www.kiplinger.com/tool/college/T014-S001-best-college-values-college-finder/school/5111/american-university/
It’s #204 because there is a bias with Kiplinger favoring less expensive state universities. Once you get to private universities, it’s ranking is similar to that of its USNWR ranking in the 60s. If you have a preference for attending a university in the DC area, then factor that in yourself. These rankings don’t take into account major area of study, and in fact, punish universities whose graduates take lesser paying teaching, theological, or government positions. I would think this would negatively impact American (government positions). These ranking services are a cottage industry and you need to look deeper.