Ramblinrev: I completely agree that if I were to factor in my time, I would loose substantial amounts of money.
I figure that with enough patience, I can fix just about anything that goes wrong on my car. It is a matter of tools, parts, and a good manual. The problem is that it takes me six times as long as an experienced mechanic who can do the job without bashing his knuckles or spreading oil over the garage walls. And the real problem is that I don't like working on cars. Some people do. My brother is constantly dinking around with his car. I've decided that for most things, it is just better to let the guys who do it for a living have my car. I'll change oil or brakes, but when the evaporator coil went out, I sent it to the shop.
I figure the hammock tarp is like that. I may be able to save $20 or raw material at the most. Perhaps $50 if I work with 2'nd quality fabrics. The manufacturer's I mentioned in my first post will do it better, faster, and certainly cheaper when you work in the cost of time.
The thing is that enjoyed making the quits. It is fun to drag those things out and say, "Hey, look at this. i did this."
So, rather than ramble any longer, I think what I'll do is try a basic tarp with some cheap dwr fabric. It won't actually be useful as a tarp, but it will give me an idea of what kind of effort I'll have to make. If I don't enjoy the process, I'll purchase a commercial tarp without any regrets.
I really appreciate all of the comments I've received. You guys are fantastic.