Cari, I totally understand what you are saying. I threw away a lot also. My 1973 Singer used plastic bobbins but I had gotten some metal bobbins since I had so many problems with that machine. So they were old and didn't think I needed that many bobbins any more. My sister tried to talk me into the pre-filled bobbins - those were a total waste of money. The thread wasn't even good enough to use for basting. Then I bought some new bobbins. The plastic bobbins for my Singer machines felt cheap and when I bought the metal ones some didn't even fit the machine, even though they were in the same package. Luckily, my mom still had quite a few bobbins when she gave me the 15-91.
My Janome and Viking only use plastic bobbins - but they are from the dealer, so if they do fail, they know I am brining them right back. So far, now problem.