Dear Teja Gadekar,
Generally property is purchasing once in a life time with hard swetted money. While purchasing please go thro the papers correctly in whose name it is there. As per your letter agreement is in wife's name and sale deed is in husbands name. Agreement is not correct because there is no title of the property. You have to make agreement with the owner/title of the property then go ahead with the purchase of property. Agreement of purchase of property and sale deed of property are different documents. Once the sale deed is completed then no value for agreement of sale property has no use but you have collect back the agreement to avoid litigation at later stage.
It my advisable that contact the advocate and go as per procedure as you one will purchase property once in life time to be on safer side and live peacefully.
Nagaraj N Nyamati