I'm lazy, so when I make soups or anything that requires, or could use stock, I buy the broth at the store. I like the Whole Foods 386 brand, it's almost always on sale for $1.99/qt, and the Imagine broth. They both have a low sodium version. The other day I grabbed the wrong kind and made a split pea soup. I had some low sodium at home and ended up using two qt's of each. The low sodium has 140 Mg and the, hmm, I suppose it would be called regular, has close to 600 mg (that works out to be about a tsp of salt). I added no additional salt. Usually I would at least add some while simmering the onions, but not this time.
The soup was just this side of being over salted. I will never buy the regular broth again. If I had used 3 qts of regular it would have been close to inedible, at least for me. I realize everyone has different tolerance for saltiness, but why would anyone use the regular? Isn't it always better to be able to control how much salt is going into your food? I have the same issue with butter, but less so as it is usually not as over salted as the broth. Still, it's such an important part of flavoring, I'd rather control the amount salt. Perhaps it only shows that I have issues. :o)