I only read some of the responses, so I apologize if someone already added this tip:
When you get to the US, buy a Sunday newspaper with the "Coupon section" and look for a JoAnn's ad. I don't think they have one every week, but they are fairly frequent.
I wouldn't have a 12 1?2" square ruler at all, if my Mom hadn't won one at a quilt show. Thanks Mom!

I went to A C Moore's on Monday to make a purchase and found I had forgotten my coupon and learned somthing very important. A C Moore will take both JoAnn's and Michael's coupons!

I had just come from using another coupon at Joann's. If you receive their coupons via email you can print out two and have twice the fun. They have a limited number of items from Fons & Porter, Dritz, and Omnigrid but you can aways buy rotary blades and who doesn't need those!

I think you could find them cheaper here. I would wait if you can.

I find the 6 1/2 x 24" too unwielding for everyday use. My first ruler was a 6 1/2 x 12" - I usually fold my fabric twice and use that ruler to cut my strips. My square rulers are the 6" and the 15" Since most swap blocks are 12 1/2" (unfinished) the 12" would not be large enough for me.

I do use the 6 1/2 x 24 to help square my quilts and cut border prints and such.

DEFINITELY - get them here and use coupons if you got them. Are you visiting a person or the country? If you are hooking up with someone, maybe they could scope out what you might need.