No, this is their NEW store card. It's like a JC Penney or Sears card. It can only be used on Amazon. They also have Amazon Visa and Amazon Discover, but mine isn't that. I'm lucky (if my grows go well, I guess) that I was even approved for that.
The prices on Amazon aren't all that terrible. The 144X3 is $48 more on Amazon than on the MH website. I understand from Tina that Alaska isn't within their free-shipping area. But this has happened before, where Amazon has listed a product as "Free Shipping" and it has turned out not to be (presumably not to Alaska). On both (or is it all three?) Amazon has refunded to me the shipping fees. That didn't come from the seller (I know, because the refund was in my account immediately after I placed the order). I called customer service before I hit "complete order", because the final order was charging shipping for a product that was listed as free shipping. So, subtract shipping from that $48, and it doesn't seem so bad.
So I'll get the 144X3 now from Amazon. If I want, I can fit a 48X3 in the closet later, and get that from Tina.