You may want to take more time to research this idea. First piece of advice is be very careful selecting a breeder. Stay away from backyard breeders & “oh we just wanted our kids to have the experience of our dog having puppies”. Find a reputable training kennel that specializes in the breed you want & puts out select, well bred litters. Expect to pay more than your mindset price & up for a well bred pup. Genetics/pedigrees from proven field dogs is everything. Then, hold on because that’s only the beginning expense.
I can’t speak as much to the pointing and flushing breeds, but for the retriever breeds I can from first hand experience. A well bred Lab pup with proven parents (field trials &/or hunt test advanced titled and a hunting background) will cost you $1k-$1,500 at least. Next, if you truly want a competent hunting dog you will want to send your pup to a reputable pro trainer. I’m not saying you can’t do it yourself, but I’ll say there’s WAY MORE to it than you can imagine. Watching videos doesn’t make you capable. Also, YOU NEED TO BE TRAINED on how to properly handle your new trained dog in the field!! Also, unless you own & live on large farm property you don’t have the space & resources. So pup goes to trainer generally at about 6 months of age to begin training. For a reputable Pro trainer with a decent size kennel and facilities, training fees will be $750’ish - $1,000’ish per month plus any other incidentals fees that will be charged to the client. Plan on your pup being there full time at least 12-18 months to mature into an obedient & competent hunting retriever. This isn’t an exaggeration or the “maximum” scenario. I’d say it’s a really good “average”. Talk to folks who have experienced this and that have worked with a pro trainer. It’s a lifetime of your dog’s hunting career journey & commitment, but there’s an amazing amount of reward.