The first place I ever bought irises on line was Wild Iris Rows.
http://www.wildirisrows.com/te...
They had a good selection and low prices, and when I received my order for 20 rhizomes I was amazed to find more than 50 in the shipping box. They sent multiples of most of the cultivars I had ordered, two or three sizable rhizomes of each, neatly rubber-banded together, and lots of bonus irises too.