How much does it cost to lease a jetliner? As the title says, how much would it cost to lease a airplane for an airline. Let's say a B737 and a B747 or similar aircraft.

I tried to contact several aircraft leasing companies but so far I've been ignored, and searching this site hasn't resulted in any answers either.
Slide 19 of this IBA presentation (PDF) shows how the aircraft's age is a factor:



Other factors such as global outlook, supply and demand, fuel prices, etc., all have an effect.

Anyway, that presentation confirms the accuracy of the data on an airliners.net thread from 10 months ago, from which:

For a 737-800 you are looking at USD 120,000–350,000 monthly.
For a 747-8i you are looking at USD 640,000–1,250,000 monthly.