There is a 'before and after' here on AP where someone took a metal headboard that was in a shape of a '1/2 round' and upholstered it. It came out beautiful. I'm sorry I can't give you any more details. You'll have to scroll through all the before and afters to find it. But I do believe there was a tutorial on it. Maybe you can purchase fabric to mimic the headboard above. (??) Good Luck.

What is it that you like most about this headboard? The color? The circular shape? The cutout bits?

I've seen wicker headboards that are nearly circular and which have an open, airy weave.

Or you could cut a large circle out of plywood and then cut out a pattern similar to your inspiration piece. Or, if your DIY skills are like mine, have a professional do it--I doubt it would cost $2500.

How about a wagon wheel? There was a trend in the 70's to turn them into coffee tables, so maybe you can find one at a flea market.

Somewhere in within the realm of people you know is a talented iron and work worker who could fashion something similar. Perhaps in exchange for tutoring or some of your other skills.
It is amazing what can happen when you put your desires into the universe.

I like the idea of hiring/bartering with an iron worker - or sculptor. I did look up wagon wheels for sale, though. Here's one: http://hansenwheel.com/store/product.cfm?cat_id=2&subcat_id=4&product_id=39

A copy can be made using a plasma cutter, any large metal shop will have one, pick the shape you want, they will do the rest.

Decide the material you want first, then I totally agree with what others have said - plywood can easily be cut by professionals for not-very-much, and metal shouldn't be too bad, either. If you live near an art school, reach out to their sculpture/interior architecture design/industrial design students; some might be able to freelance you a piece for not much at all, and they often have access to discounted materials and facilities with a lot of handy tools. Some schools even have fancy ad boards that you can post jobs to online!

could you achieve the same look with paint? The anthro one is gorgeous but I think it really pops because of the white on the dark paint. If your walls are another color, you might do better by getting to choose your own color!

here is a painted version of a round headboard (white on green)

I just saw someone use a rubber entrance mat as a wall hanging, I am thinking you should look at the half circle mats for outside your door, maybe there is one big enough that you could paint it and hang it behind the bed.

play first: get a piece of foam-core, cut into the desired round or semi-round. lay spare lace over it & spraypaint negative space, then peel off lace, or use thin utility knife to cut out negative space, or glue on textured fabric/trim/hardware/mystery bits in pattern like collage w/ paintover optional. sturdier: can purchase plywood from a lumberyard & pay a few $ to have it cut into semi/full circle (can be done at met lumber on 11 av in manhattan for <$100 exterior edge only. not sure met does cut-outs).

If you want lightweight and budget friendly, I would suggest some pliable tubing from a hardware store, like a garden hose but stiffer, bent into a semi-circle and secured to a dowel or piece of PVC pipe cut to the length that would be the width of your bed. If you had a set of twin beds, you could cut a Hula Hoop in half and make two! Then start a large, but fun, macrame project, using rope or ribbon or even strips of fabric, creating a web of twists and knots until you have the look of wrought iron. If you don't have space to paint, use black rope or yarn. (You can paint yarn and rope, but if the yarn is synthetic - consider an acrylic or water-based paint.) You can wrap the tubing with the yarn, or use black electrical tape wrapped around the tubing to cover it. The finished product should be lightweight and easy to mount on a wall.