HDBRS, I reload one ounce 12 ga shells for less than $5 per box, 20 ga shells for less than $4.75 per box and 28 ga shells for less than 4.25 per box. That includes tax and/or shipping on the components and assumes shot at $40 per bag. I don't include any cost for hulls because I can get WWAA or Rem Premiers and Nitro 27's for free. I believe that my reloads are as good as the factory ammo. In my case I believe that I am saving some money but I also enjoy reloading as another hobby. I'm retired so I don't try to value my time in an economic sense.
The PW 375 loaders (such as the one that Rocketdog is selling) are, in my opinion, the absolute best single stage loader available. I have four of them and recently gave away a fifth one. I have two set up for 12 ga, one for 20 and one for 28 ga. It's easy to take the four mounting bolts out of the bench and trade the loader out for another one. They are not fast. If loading a lot of shells in a short period of time is your objective then the 375 is not a good choice. But if precision reloads is your primary objective these loaders are great. I load between 6 and 7 boxes (150-175 shells) per hour.
I think that I save at least $1 per box on 12 ga and about $1.25 per box on 20 ga. I save about $5 per box on 28 ga I think but I haven't priced factory 28 ga in several years.
Assuming that my figures are applicable to your situation (I buy in bulk - 5000 primers, 8 lbs of powder, 5000 wads, multiple bags of shot) then I believe that you would save money and the price of Rocketdog's PW 375 would be covered in short order.
My main thought though is that if i am gonna start should i buck up for a new progressive reader first. i have been looking at hornadys and mecs. new pws and higher end stuff would not be worth it considering i am a new casual transporter. maybe 100-150 shells a week