Helen,
In my slight experience with bluebells, I wouldn't buy anything but a thriving plant.
If you're into mail order, let me recommend Sunlight Gardens in Tennessee. I've been exceptionally pleased with a couple of hundred dollars worth of orders from them (no disappointments at all).

Here is a link that might be useful: Sunlight Gardens

Our mertensia has been blooming for several weeks and is still beautiful. One of the first perennials we put in, over 15 years ago, it has spread and become more durable thru the years. Ours is under a pin oak tree. We do very little there except water when excessively dry. The blue bells are mixed with bloodroot, spiderwort, Solomon's seal, day lily, coral bells, Jacob's ladder, crocus, star of Bethlehmem, lirope, columbine, and wood betony. I agree I would much rather pay for a mature perennial than a small dormant root. In the same small door yard we have weeping yaupon holly, blue angel holly, and box. EP

If I remember right-you move them in the fall not the spring-when they are dormant.I agree about the poor quality plants.You are better off getting a better one.Posy Pet

I got another one at Ozark nursery for 5.49. It is in a one gallon pot, but is small. They had some healthy looking annuals; I bought some red salvia and periwinkle. Also they had soil for $8 a small scoop. I got two scoops in my little pickup. I ordered top soil in early spring but the guy never came. A dump truck load may be cheaper, but I can handle the smaller amount easier. I've already used it for
asperagus and tomatoes and now I have to get some more dirt. Both Ozark nursery and the Oaks have cats lying around. One at Ozark nursery was in a bird bath.