Be grateful the property is under the contract, otherwise you would run a risk of severely overpaying for it.
Most/all homes sold as rent-to-own are sold for MUCH higher price than homes sold the traditional way in the open market. The sellers are taking a huge risk by *renting* to someone who may or may not purchase in the end and they want to be compensated for that risk and any potential damage done to the property.
I suggest that you use the next few years to do whatever you need to do - down payment, credit, etc - so you can purchase on the open market. As a reward, you'll have a huge inventory of homes to choose from :-)
Rebecca Thomas, Realtor
Keller Williams Realty Greenbrier
1100 Volvo Pkwy Suite 200
Chesapeake VA 23320