Doh!

After some searching I found a bedspread I thought would make a nice wedding gift for my sister and brother-in-law to be.  I found it at www.e-patternscentral.com and this is what it looks like...

Where the problem comes in is that in adjusting the pattern to make it a king size spread means I require an insane amount of yarn.  I don't have a problem with that, nor with the fact that I have just under a month to complete it.  The real problem is that I doubt I'll be able to find enough yarn to buy in one stop to complete the project.  I'd need about a dozen of the pound-size balls of yarn, give or take...and so far I cant' find nearly that many of the same color.  Had I thought of it a lot earlier, I could have ordered it online, but I don't have enough time to wait for delivery now.  There are a couple of other stores I can check, and if that doesn't work I'll have to switch to a regular size afghan.  Doh!