If you are talking about furbabies, I have one of each. All I can say about buying one, is be sure of whomever you are buying from. Stay away from pet stores and puppies in ads on craigslist, or the news paper or similar places. You want to buy from someone that cares about the specific breed and health standards. They needs to have the parents genetically tested and vet checked before breeding.
When my husband and I were ready to get another dog, we looked for a rescue. There were no Boxer rescues near us that had a young female. And when I say near me, I mean in less than a six hour drive. (12 hours round trip) After months of looking, we came across a breeder who had one last pup. We took her.
Then when we were ready for another pup I kept my eye on several rescues. This time we were looking for a male. Unfortunately there wasn't any that would fit in with our family. Then someone contacted me about a someone rehoming their pup. They had rehomed him once before, but the person apparently didn't know what they were in for. They abandoned him at a vet. The vet sent him to a shelter where he did not do well. The original owners found out and got him out of the shelter. He was skin and bone and a nervous wreck. The reason they rehomed him to begin with was their jobs had changed and they were gone for 10 hours a day. Since that was still the case they still needed to rehome him. I was contacted and I went and got him that weekend. He is now 10 lbs. Heavier and much healthier. But he is also on Prozac. We cannot leave him (and our girl) home alone for more than 20 minutes without coming home to damage. I am a housewife who is home most of the time and my husband is retired, so it is rare that we need to leave them home, and when we do we have a dog sitter.
While not every rescue is like him, not everyone can handle a rescue with needs. Everyone needs to realistically evaluate what they want and expect, and get their pup according to that.