How does this scenario work?

[Marc L.]

Craigslist ad:
For Lease Purchase - $2,000 down/$600 per month OR $3,000 down/$500 per month for 15 years and the house is yours!! I pay the insurance and taxes and you take care of the maintenance.

Is this legitimate or is it a souped up way to get a non-refundable deposit? I'm assuming the tenant/buyer never has the option to get a traditional loan to buyout the rest of the lease.