Question regarding Property Registration

I have decided to purchase a apartment worth 71,35,150 which is the amount in agreement cost. I received the below mail from builder and confused which option I should go with and whether either will have any legal implications when I try to sell the apartment later point in time. "With regard to the minimum value and full value amount towards sale deed registration, the details are as follows. The minimum value to be incorporated in the sale deed is based on the apartment cost shown in the valuation certificate, which is to be made part of the sale deed, issued by the approved valuer and the value for the undivided share of land as per the prevailing fair value. Regarding the amount of Rs.4,10,132/- mentioned in the final bill towards the registration expenses, the calculation is as follows:- Sq.Ft. (1399) x 2250 + Land value for apartment (Rs.7,73,573/-) x 10% + Rs.18, 000/- towards the documentation fee and accordingly the total amount mentioned is Rs.4,10,132/-. The current fair value for the undivided share of land allotted to the apartment is Rs.7,73,573/-. If you require we can do the needful to register the sale deed showing the agreement cost, i.e., apartment cost + land value, amounting to Rs.71,35,150/-. If so, kindly note that the registration expense would enhance. As per the agreement, the land value is Rs.6,74,700/- and the apartment cost is Rs.64,60,450/-. However, the fair value has gone up and the prevailing fair value for the undivided share of land allotted to you is Rs.7,73,573/-. For registration purpose the prevailing fair value has to be considered and therefore stamp duty and registration fee will have to be paid for Rs.72,34,023/- made up of Rs.64,60,450/-(apartment cost) and Rs.7,73,573/- (revised fair value). Thus stamp duty @8% and registration fee @2% for Rs.72,34,023/- would come to Rs.7,23,402/-. In addition to that, towards documentation fee you will have to pay an amount of Rs.18,000/-. Thus the total expenses would be Rs.7,41,402/- ( Rs.7,23,402/- + Rs.18,000/-). Accordingly, the difference amount of Rs.3,31,270/- needs to be paid (Rs.7,41,402/- minus Rs.4,10,132/-). Upon receipt of the said amount we can proceed with full value registration as mentioned above ".