Hi kobelco - Welcome to Beat the GMAT!
These can be difficult questions for sure. The main reasons that a school's ranking matters are that it attracts higher-caliber students, oftentimes there's more funding available for scholarships, and it generally will get significantly more attention from recruiters than a lower-ranked or unranked MBA program. (These are all correlated factors, not causal, of course.) So the standard advice is, go to the best school that you can in terms of reputation. This typically means you'll have more opportunities available - and where this can matter the most is in your first post-MBA job. That's because the salary you get at the first job out the door of the program will largely dictate your earnings trajectory for the rest of your life. So yes, there's a $20k difference in tuition, but if you can get an additional $5k (or more!) in starting salary, then Carlson will make up for that pretty quickly.
Now, it really really depends on your locale and what the employers in your area, and in your industry, care about. Sometimes the difference doesn't matter so much.
In fact, we recently responded to someone with a similar question in the LA area and we basically said to go for the cheaper school - the opposite of what we're suggesting to you. You can see that thread here:
https://www.beatthegmat.com/pepperdine-v ... 25268.html
The main reason for the difference in our answers is, Pepperdine is not considered as good a school as Carlson, and we don't see Pepperdine as worth $25k more than LMU. But that's our perspective as an outsider; EssaySnark is not an employer in the LA area (or the Twin Cities area) who's looking to hire these graduates. THAT's really where you need to be doing your research.
Start with the schools. Get their employment placement reports. Talk to their career services people.
Then, talk to the companies. Reach out to the HR departments of the companies you'd want to work for in the area. Or just go talk to your boss, or the CEO of your company if he/she is accessible. See what other people say about these two schools.
You can get a great feel for how they're regarded through conversations like that. It should help you understand the differences (way more than some anonymous 'Snark on the interwebs can do!!).
The other approach of course: Apply to both schools and see which one(s) admit you!! That could make this whole thing moot.
Please come back and let us know what you find, and what you decide to do. Will be interested to hear your strategies!
EssaySnark