Short term rental premiums?

[Chris Stromdahl]

One of my tenants is requesting a three month extension to the lease so that he and his family have some time to buy a house.

I would prefer not to do this, but as a landlord, I do want to consider the needs of my tenants/customers.

Would you apply a premium to the  monthly rent for this period?

What is a reasonable amount? $75, $100, 10% of the monthly rent?

Or, would you not apply a premium beyond normal market rent increases?

Thanks, Chris