My husband is a general contractor and he goes through trousers like it's nobody's business. :(

The only construction pants that even last him more than a few months are the Carhartts, Double Front.  I found them at a nice price on Amazon.  Generally I will get them locally and cannot find his size (29x30) or a good price and have to order them in at the stores.  I found them on Amazon for about $10 less than locally.

And, for some reason, I think they have even lasted longer!  I think it usually takes him a about 4 months to wear out even the double front Carharrts.  He's had these since March and they don't yet have holes in the knees! (No matter what I tell him, he won't use knee guards in his construction and he is constantly wearing out the knees in his construction pants - argh!!!!.)  I had been thinking to try the Carhartts without the double front but I am wary because he wears out the double fronts usually pretty dang fast so I opt for the more expensive but more hardy double fronts.

Anyhow, when it is time to get more for him, I will be ordering from Amazon again.  Happy with this product, as is my husband.