Ultra low cost arduino

Hi everybody!

I just wanted to know if there is an ultra low cost version of the arduino uno, i mean a derivate/copy. I need to do a test that probably I will burn some of them and I'm with a little budget. Do you know any project?

less than 9$ would be amazing...

Yes, the “Arduino Pro Mini”, for about 3 dollars.
But you need an extra usb-to-serial converter to upload a sketch.