Should I buy Game of Thrones?

So I downloaded a sample of Game of Thrones to my Nook and it's good.  Pretty good.  Now I need help, from those of you who have read it already.  Should I buy it?  It's a four book series, right?  This looks like a big commitment, in money and time.  Just the sample has so many characters already I'm going to have to make a list to keep them all straight.  But I have heard so many great things about it.  Normally I would just consider getting from the library but lately I have been doing all my reading in bed and I can read the Nook in the dark, and not disturbing my husband with that pesky book light.
Anyway, what do you think?  Is it worth the time and money? Assume I have the budget to buy one a month but it means that's the only e-book I can buy for the whole month.  Types of books I read are mystery/suspense/thriller.  I'm not a big fantasy reader though I did love the Harry Potter series (which is not available as an e-book as you well know).  I love Lee Child, Harlen Coben, James Rollins.

Thanks for any comments but please no spoilers.

Also, if interested in my book Secrets, but not sure it's for you, links to reviews are in the box to the right. If you decide to buy Secrets, buying through the Goodreads links donates a portion to charity.