This seems to be a pretty pragmatic approach - it avoids spending a lot of high tuition dollars and effort on the freshman/sophomore generic weeder courses and focuses the high return on effort/investment upper level courses that are specific to your area of study.
I wish I could say it was my plan all along, but it just kind of happened.
But yes, from a credential standpoint, a masters program can upgrade your prestige, for sure. Although it would be important to note that there are social aspects of the Ivy League in undergrad experience that aren't the same in grad school (and vice versa), if that's what someone is looking for.
