Quilterj, I've not seen these in JoAnn's (I've been in their stores in WA, CT, AZ, & WI). Go to the amazon.com link in the post from Wesing and then go to their store. The prices are what I paid at the sew expos for mine. Be sure to get the foot package also as it helps with your posture.
To Bourvel, have you tried using an adjustable office chair to rise up to the sewing desk level? I love the chair I got to be able to adjust to the 2 heights I have when I sew on 3 different machines.