I have been a Danner boot user for many many years.  I have had three or four pairs over twenty years.  This my new favorite Danner boot.  I have stayed away from the side zipper but have completely changed my mind.  This boot is well made top to bottom.  The steel toe & quality soles are great to have.  The side zipper makes it so easy to get on & off quickly.  Just a perfect boot for my job.
So the cost is a bit higher then many boots out there.  The quality & fit of Danner boots is well worth it.  They well easily last me many many years.  I work 60 hour weeks but make it a point to take care of the boots.  Clean them, polish them put some basic care into them & they will last you for years & years.