I own a new model Blackhawk and a Super Blackhawk. I have had the super blackhawk for over 30 years. The new model blackhawk is 2 years old. I bought the blackhawk for the same reason you are considering a 357 mag. I can afford to shoot it when ever I please. 44 mag ammo is expensive and punishing to shoot. Finding 44 spl ammo in this area is like searching for hens teeth.
When I bought the super blackhawk both calibers were plentiful and affordable to shoot. I was living in south LA when I purchased the SB. There was only one gun shop in the area. Most of my ammo came from hardware stores or country stores. Now I live 25 miles from a metropolitan area with 2.5 million people in it and finding anything is a PITA. 20 years ago deer hunting was the number one participant sport in NC.
Both guns have given me great service. Once you take the plastic grips off the blackhawk it is a much better looking gun. I got a set of rosewood target grips made by ruger for $30 plus shipping from Jack first. I would avoid the hogue monogrip. It looks real nice but the gun doesn't shoot well with a rubber grip. Revolvers were meant to rock in your hand to help absorb recoil. The monogrip actually increases perceived recoil.
To get the best out of a 357 mag you need a six inch or longer barrel. The 6.5" barrel only adds an ounce of weight to the gun. You will get a much better sight plane and your ammo will perform better.