Here's a very simple (though slightly time consuming) knock off. It's just a simple pillow with a star embroidered in jute and decorative metal rivets.
The Pottery Barn Version:
I initially tried to embroider with a hemp thread, and while it worked better than I expected, it was just way too tedious. I was ready to go out and spend the $50 for this pillow. When I switched to thick nubby yarn, it was much much easier. So, yeah, I cheated. But that's what knock offs are all about, right? Plus, with all the supplies I purchased, this pillow came to under $10. And I have a ton of leftover fabric, yarn, and fiberfill for future projects!
Here's a short tutorial so you can see what order and direction to make your stitches.
First, draw out a double star on your pre-cut pillow top like so:
Now draw lines capping off each point where the tip of the inner star's points reach. That made no sense. Just copy the red lines.
Your first round of stitching is going to be around the inner part of the star, with the satin stitch direction following the green arrows:
When you're done stitching this part, you should have something like this. You can see that the stitches extend past your red lines if you choose to continue the stitch all the way up, and that's ok.
Now stitch over the points of the star, in the direction indicated by the red lines below:
Your stitching is done! Sew or glue on decorative metallic buttons or brads at each point.
Now sew your pillow top to your pillow back (leaving a small opening), turn right side out, stuff, hand-sew the opening shut, and you're done!
Just don't try to take a nap on it.