here defendant-appellant celestino c. juan himself in the negotiations for the sale of his property to the state for use as a school site offered it for the price of p190,000.00 ( p170,000.00 plus bank loan of p20,000.00 ) , with a down payment of p90,000.00 and the balance of p100,000.00 payable within one year , as per his letter of january 28 , 1963 .