And what else has the landlord "offered" to do?
Why is the seller willing to do this?
A rent with the option to own arrangement usually favors the seller.
There are a number of pitfalls that a buyer needs to beware of.
If you can't qualify now for a loan, or don't have a down payment, and that's why you would consider this arrangement......make very sure everything will come together for you at the end of the lease, or you could forfeit any upfront /deposit money.
Also - with this arrangement, the price is agreed to now - do you want to guess what the valeu will be a year or so from now?
Also - why hasn't the home sold as yet? Is it overpriced?
Usually sellers who are desperate and can't sell their homes now may turn to this sort of option.
Is the seller financially sound?
If they stop paying the mortgage, you will have no recourse...and they will have your money.
Make very sure you understand everything that caan come into play with this kind of deal.
Absolutely hire a real estate attorney to make sure your rights are protected............in my opinion, rent for now and buy when you are financially able to do so.