Validity of sathe khat for agricultural land in maharastra

i plan to buy the agriculture land in Maharastra from an agent who has registered power of attorney to execute the sale. However since i dont have enough money now to pay him in full i have agreed to pay 30% now and balance in 12 months time. The arrangement is as follows: We enter into a SATHE KHAT registered agreement with validity for a year. and once i clear balance payment anytime within 1 year we would then do the sale deed [khareede khat]. My questions is: 1- is this good arrangement to buy an agricuture land? 2. what if agent refuses to execute sale deed after recieveing maximum payment? 3. whats the strength of SATHE KHAT in this whole deal? Note: i am a farmer and have all valid documents to buy a farm/agri land in maharastra. Appreciate your response..