Get an attorney you are not qualified to do this yourself.
What is the interest rate?
How much is going to the down payment?
What is the price?
Can you justify the price?
Will you be able to get a loan when the option is up?
What happens if you don't buy it?
Who is responsable for repairs till you get a loan?
How much is insurance? (not what you pay, the actual cost)
How much are the taxes?(not what you pay, the actual cost)
Have the disclosures been filled out?
these are just some thoughts, if you don't know all the answers then get an attorney.