MatataMingi:
As VJ has pointed out, the basis for pricing the property is the value of the land, and not the rent paid.
Given how valuable the land is, you are better off not repairing the house but thinking of developing the land with townhouses/apartments. The units you develop will most likely be worth 2 times to more than 4 times what you paid for the land, depending on what you construct, when you start the project, the cost of financing, your available capital, among other factors.
You may want to get an informal valuation opinion from a valuer or real estate agent who is familiar with Kilimani. Recent comparable property sales should be able to give you the appropriate market price of the property.
Also, just to emphasize, the answer to your question about the basis for pricing the property is not the purchase price to rent ratio.
-Fair Car Dealer