Thank goodness there are now companies who make tunnels just for us agility junkies at much more reasonable prices. They come in a variety of colors. The only color I would not recommend is red. Red seems to fade very quickly and you end up with a whitish yellow. Here is couple of web sites for buying equipment.
Plans are for easy to do back yard equipment.
They also have a great magazine on agility. I would recommend this as the number one reading material for agility. If you do a web search for agility equipment, you will be amazed how many placed are out there. I personally do not like the PVC jumps and equipment. It blows over in the wind and breaks down in time from sunlight.