Well, i have lots of Craftsman tools, and lots of sockets made in Korea, and lots of hand tools such as wrenches made in Korea, as well as USA made tools.
I have no experience with Dura-last, but the price was right on the one you turned in. I'd say, if they guarantee their tools--they must be ok!
For lawn mower work, i don't think you have to spend a lot for fancy tools. I bought a 1/4 inch drive ratchet at a local hardware chain, and it works well.
I went to Costco with a friend one day. I saw a complete hand tool set, with everything the home mechanic could need, for $100! And--guaranteed, to boot! Can't beat a deal like that!
Now, if you are going to be a big truck wrench twister--then you ought to buy better stuff! And, from the guys in the tool trucks! They have to eat, too!