I have ordered from peony nursery. They have some very nice varieties and the prices, even with shipping, are good. They are not very sizable roots in most cases, but will bloom with time. I would not buy tree peonies from them as they seem to be either too dried out or something, in that they just don't do well. I wouldn't say it is my "go to place" but I have purchased varieties that you can't find here in the US easily.
One thing is nice in that you don't need a permit to get them. And $25 overseas shipping is pretty much the deal of the century. Also they have been very responsive to emails. No ghosting you with these folks.
Gary, that is strange that the post office sent your back. I've never had to sign for them or anything. USPS just leaves them right on the porch.