Seller financing can be a great idea or a terrible one, depending on a host of factors.
Generally, sellers are willing to owner finance when they would experience a significant taxable event and generally buyers seek owner financing when conventional financing is unavailable to them. Otherwise, conventional financing is almost always cheaper and easier.
But if you do choose to go the seller financing route, just be careful as there are many different forms. If the seller has a mortgage already and you are paying them in an arrangement called a ‘wrap,’ then you have considerable risk if the owners fails to make the payment. If you engage in a ‘contract for deed' arrangement, then you really haven’t purchased the home as the seller maintains control of the deed — and this can also be quite dangerous to the purchaser. And these are only two of numerous scenarios that comprise ‘owner financing’ — there are many others.
At the end of the day, owner financing can work, but only if the availability of traditional finance is unavailable. If you require owner financing to purchase, you end up limiting yourself in choice and introduce more risk than you should into the process. If the reason for needing owner financing is temporary, consider waiting, or consider sitting with a lender who understands grant programs and other lending packages that might not be as cheap as traditional finance, but offer more protecting than allowing the owner to be your lender.