Budget minded tires for mixed recreational riding. What do you think of these?

[Myosmith]

My wife and I are both newbies with a pair of used Trek mountain bikes, an 820 and an 830. Her bike needs tires and both have knobbies that we would like to replace. We are on a tight budget (that's why we both got used bikes) so some of the first choices are probably more than we want to spend right now. I'd like to replace all 4 tires for under $100 if possible. We do 80% of our riding on paved roads with the remainder split among gravel, dirt, and turf. I found these online. Any experience, thoughts, insights?






http://www.biketiresdirect.com/product/michelin-country-rock-tire