First, you could save a animal life by adopting from a shelter or rescue organization. Each year thousands of healthy and well behaved animals end up in shelters as strays, relinquished animals, and impoundment. Animal shelters take in about 40 animals every day. As new animals arrive, some of the animals who are not adopted will be euthanized because the resources are limited. So each animal adopted is a life spared.
Second, adopting is more cost-effective than purchasing. Most shelters provide all necessary shots and spaying/neutering before the animal goes home with you. Spaying/neutering helps to end the tremendous pet overpopulation problem, is healthier for your animal and saves you time and money.
Last, you could avoid supporting the animal industry. In Taiwan, millions of animals are neglected, abandoned, and euthanized because there are not enough good homes for them. At the same time puppy mills continue to flood the market with animals for sale. This makes no sense. Animals are living beings, not commodities to be bought and sold...and then disposed of at shelters. For those concerned about animal welfare, adoption is the only sensible way to get an animal.
Although you can't adopt them all, you could give one of them a loving home. Besides, you will be an example to others, and they may become inspired to visit a shelter. If you've never saved a life, just do it now. You will feel good about it. And the dog or the cat you adopt will remind you everyday that you've done a wonderful thing.