Hi Jose.
I got mine at Sears in 2010 and they are still functioning. I think I paid a bit less than the price in this link. That being said, $13 per hose with a 7 year warranty isn't too shabby. Looking at your drawing, each bed could have 3 runs from 1 hose. At the current price, your 16 beds would require an investment of a little over $200 for the hoses.
http://www.sears.com/craftsman...
I bought a couple rolls of inexpensive weed block ($5 for a roll of 3ft x 50ft) and cut them into roughly 8in widths. I placed the strips under and folded over the hoses as I laid it on the soil and placed the mulch on top of the covered hose. That worked very well for keeping the dirt away from the hoses. So far that is all the maintenance they have gotten. I add mulch each year as it does break down. When I add mulch I do turn the water on so I can make sure the water is still flowing.
I hope that helps you. I am quite happy with this set up. and it seems that from the reviews in the link, the majority of the reviewers were also pleased with the product.
