“13. That the lessee shall not sublet or part with the possession or transfer his right, title and interest in the said house in whole or part by way of sale, exchange, gift or mortgage or otherwise without the prior permission of the Board in writing which it shall be entitled to refuse in its sole discretion or in the event of consent being given the Board may impose such terms and conditions as it thinks fit and proper and the Board shall be entitled to claim and recover a portion of the unearned increase in the value (i.e., the difference between the cost paid and the market value of the land and the house) at the time of sale, mortgage, transfer by way of gift, assignment or parting with the possession the amount to be recovered being 50% of the unearned increase. The decision of the Board regarding the market value of the land/premises shall be final. The Board shall also have the preemptive right to take back (purchase) the house/premises from the lease after paying an amount equal to the premium/cost paid by the lessee, less/depreciation and 50% of the unearned increase in the value of the land determined in the manner indicated above.