What's the worse that can happen?
You could be loading light match loads of 3.5 grains with a really light flaky powder and a powder thrower that happens to throw an extra light load. Then when shooting a competition that light round happens to be the first of two in a double tap. When you are averaging about 2 tenths of a second split times between shots, you have already pulled the trigger again by the time it registers that the first shot didn't sound right.
The result could be that the first round had just enough power to cycle the pistol yet only push the bullet half way down the barrel. The second round may have pushed it through so that both hit the paper, but left a large swell in the barrel at the point they collided forcing you to purchase a new $250 barrel.
It could have been much worse so be thankful all 9 1/2 fingers are still there, but take it as a hard lesson to
ALWAYS check your cases to make sure the powder shot is right before loading and seating the bullet.
It isn't a bad thing overall. As far as saving money I really couldn't tell you as I am not up on the prices of supplies. Judging that a $9 box of 9mm is now in the $30-$40 range, I'd say it definitely has the potential to be cheaper. I know I saved a bit back when I was loading, but I was also going through between 300 and 500 rounds each weekend training.
I could also play with my loads and make them work better for what I was doing. I kept lighter loads with heavier bullets in my handguns to give my recoil a snap instead of a jump allowing for faster followup, and I loaded for my rifle where I could sight at 50 yards, be an inch high at 100, back on at 150, and an inch low at 200. That same load could also shoot a quarter of an inch grouping at 200 yards off a bipod if I was doing my part.
It takes a little time to do, but not a bad way to spend a few winter evenings. I had a hand primer I would use and sit and watch tv while priming a bunch of cases.