We are still working on a retail price, but for a system like this, probably around $3,500. The price on just the tray is going to be around $750, if we can get a large volume run, we can probably drop the price to $600. The trays come in both 32 cubic foot (12" deep), or a larger 64 cubic foot (24" deep). We also use HDPE, not ABS, so clean up is as simple as using a water hose and your thumb. You can clean a tray in under 5 minutes.
http://www.youtube.com/watch?v=c9b7WvgxhpI
You could build your own PVC manifold, but our production versions will come with a stainless manifold. The 1/2 sized pipe tends to use more water than a 3/8's pipe size. We are still using the Teffens. They've proven the most reliable. We also have our nozzles pointed up.. not down. We still get decent root hair growth. Decent enough to grow Romaine to .31 lbs (over 1/4 lbs) in under 28 days (24-25 days with 24/0 light cycle. The system used 11 gallons a day drain to waste, or 3 gallons per plant. That's almost half what recirculatng systems achieve (6-7 gallons). We've spent close to $50K on R&D so far getting this right.
Here's some root porn.
28 Days for lettuce..