These types of arrangements raise a host of issues from a consumer protection standpoint.
Legally speaking, a rent-to-own agreement does not involve "credit" and therefore does not trigger the protections afforded under the federal Truth-in-Lending Act. That being said, many states have recognized the predatory nature of these types of transactions and have enacted laws that require the same types of disclosures that accompany a typical credit agreement.
So while it might not be considered predatory in New Jersey, it can be in New Hampshire. The Department of Justice published an excellent resource on subject, which is available here.