Here in the U.S. leases are only available from the car dealer.
Most models are only available for lease periodically… that is they are not available all the time.
Leases tend to be competitive for like models with the only thing separating them price wise is the mileage you want applied over the life of the lease.
Here, most dealers offer either 24,000 or 36,000 miles for the 36 month leases and the average four-door sedan, non-luxury are in the neighborhood of $300 per month (with adjustment for the mileage package selected) with either a trade in or roughly $2,500 cash costs to close the deal. The owner pays sales taxes and licensing costs, of course, (as well as insurance).