For the most part Filson stuff is only initially expensive. My experience is that it both out performs and more importantly out last other stuff so the cost per mile is lower than other things.

Really though the vest concept is just a great way of providing both coverage of your tools on the belt, storage of items that are hard to carry otherwise (tarp or plastic shelter, wool hat, wool gloves), and provides a great barrier to temperature changes. If I had to exit my building with only my on-body I would have shelter to be warm enough (not warm as I would like in the winter but enough) and dry, this is way more than my work mates.

I bought my current vest over 4 years ago at $100....still going strong and well worth the $25 per year.

A decent woolrich or like vest will serve just as well and may last as long but my Filson Vest to me is the most valuable kit item I have ever found.