If the folding step was created by specific person, and apply for copy right, then it is protected and you can't copy or sell it.
However, origami style like cranes, butterfly....common style are nothing new. I was learned from my partner, and they learn from their parent. Those are widely know, so it is okay to sell, however, if someone copy right a specific item which is create with need of origami crane (for example : using the created a specific picture that he/she designed) than you can not copy the same design, that is nothing to do with the copyright of the crane, but the copyright of that picture.
I hope I didn't confuse anyone. If I did, I am sorry.
This is what I learned when I start my business.
By the way, origami flower bouquet is not copyright, because the also have long history in origami world, any new way to fold the flower may be, but not the basic folding method.
Wingy