What value my armchair?  

You pic doesn't work. Just...
You pic doesn't work. Just post the address to the pic in the 'associated web images' part that is below where you write your message.

I tried posting the address for the pic myself
but it still doesn't work. Make sure you have the address correct.

.
.

Do it this way
down in the web images

OK...I copied it
and put it in my own photobucket.com gallery

I don't know who made it
but's totally different from a Wassily Chair.
Here's my knockoff

Huh.
Well, I like that well enough.
If anybody's wondering, the design of the Wassily was clearly meant to address, fully, the issue of avoiding body contact with any of the tubing. It satisfies this imperative, at least -- even if the looseness of the arm straps means continually adjusting them, at least in my limited experience.
The chair posted by the author of this thread is a good example of what Breuer was trying to avoid: a cross bar below which the leather (or canvas) sling(s) depresses when sat upon, bringing the steel into painful (or at least annoying) contact with flesh and bone.
Of course the Wassily is also an essay in planar composition -- but the functional aspect of that composition is more than a happy accident, I feel quite sure.

Thanks to the dude who...
Thanks to the dude who posted my pic.

If only
one picture of a chair is available, it might want to be a side view, which immediately shows the posture of the piece and its general shape, perhaps a bit better than a front or rear view would do.
I guess the seat and arms of this piece both slope down to the rear ? It does seem to be unusual; I can't recall seeing one like it.
I assumed that the front crossbar would contact the underside of the knees; perhaps the chair is low enough that this doesn't happen ? I bet it does if you stretch your legs out ?

They slope down to the rear, but when you're sitting up straight, I don't find the crossbar a problem. I've watched movies in the chair without incident.