Some students start out at a public university's law school and then want to transfer to a more prestigious institution. Schools with excellent reputations, such as Harvard and Yale, provide first-class educations. Also, your career might well benefit from transferring to a more prestigious school because large, prestigious firms typically favor graduates from equally prestigious schools.
The rigors of law school are quite trying, and some students find themselves wanting to be closer to family for support. Others might need to transfer because of a spouse's job transfer or to take an internship in another state. These are all valid reasons for transferring.
Even with financial aid, law school is expensive. Transferring either to a less expensive area or a school with lower tuition might be tempting -- and even beneficial in the short term.