I have to agree. Several years ago, I made my own. the plating has to be at least a couple thousandths of an inch thick to be worthwhile.
After playing with home copper plating of lead bullets (I'm an electrochemical hobbyist), the end effort is simply not worth it!
You need much more than just copper sulphate solution. You need a dc power supply (battery charger) capable of delivering several amperes. You need various acids and cleaning solutions, a means of agitating, rinsing, and polishing bullets, and tumbling them while plating. You need plastic, ceramic, or glass vessels for the solutions. I got my supplies from contacts in the electroplating industry.
EPA , state, and local regulations are murder! If you get caught pouring your used chemicals down the drain, they will have your buns!
It's MUCH easier to simply buy from a reputable dealer in copper-clad bullets.