Make your own baby food.
It is pretty easy. Buy the produce you wish to feed your child. Cook it, skin it, whatever it. Puree it to the recommended consistency. Chill in an ice cube tray for longer term storage. Feed child. Cackle with laughter at your savings over organic baby food. My wife recently made 18 oz of baby banana food with a bunch of bananas that cost $1.59. Compared to the baby food at that Amazon link, my wife's per oz cost was around .09 vs. the packaged cost of .22 (excluding shipping). Huge savings, same organic feel good vibe, except you know no preservatives or additives are in the food.
I am reminded of a previous argument I had with how easy it is to eat well or a prepared meal, with of course whining by a bleeding heart lib in the comments section, and this is no different. This takes very little time and investment. Buy a blender or one of those hand power mixers, which are useful in general in the kitchen. For banana preparation, all it takes it a fork to mash the bananas properly. It takes time. Spend 15 minutes prepping your kid's food rather than watching TV, surfing the Internet or being an ass, and save some money. It really is easy. It just takes a small bit of effort. In the end, it's a benefit for your kid and your wallet.