Hello and Welcome to the forum!
I'm not too familiar with Navajo rugs. However, from what I see of this rug, I can tell you it is absolutely hand made. The style of weaving is called "Kilim" sometimes also spelled "kelim." washing a rug like this should be approximately $2 per square foot, maybe a little more or less depending on where you are. The colored thread which makes the "pile" of this flatweave appears to be a nice quality wool, and the foundation cotton. As for age, its tough to tell unless seeing it in person, something like this I would imagine no more than 30 years old.
It appears to be in decent shape, although the fringe has been tattered pretty far down. This isn't a big deal, but be careful washing it as it should be secured. you can shampoo it yourself with cold water, but it's best to leave it up to a professional in case dyes run or other. It's a type of kilim I'm really not too familiar with. I couldn't even venture a guess as to where it was made because so many of these are made everywhere. I think the design in the border is supposed to be a flower or rose
What size is this rug? it looks very large and a little long, maybe 7'x13 or so?