Yes i did do it myself ,it is a more bigger now than in the photo, not a lot to it a bit of wood from wickes and some wire.
I think the best wire to have is 16g 1in by 1in and to paint it black , then you will not see the wire so easy and is a lot better for seeing the cats playing.
For cost it is all down to how big you are going to have it , but it will cost a lot less than getting someone in to make one for you if you can do it or some one you know can do it. And the one in the photo only was about two days to make