>>57463
As someone else said, it entirely depends on what you need or want them for. Are you looking for incontinence reasons, being a little, fun, wearing discreetly in public, etc?
If you are looking for cheap pairs to just wear for fun/fantasy I would recommend checking your local goodwill or secondhand store. They normally carry new unopened bags of diapers and typically are the cheapest option you can find. If you don't find at least one pack there at any given time I would be surprised. You can buy a pack for a few dollars and wear one or double up them if you want some extra bulk. I've bought them this way for my little and the cashier doesn't even bat an eye so don't worry about this in case you would be worried about what they or others might think. This is just a normal transaction and unless you make it weird then no one else will. If you still feel nervous then you can just go out to a store father than you normally would to guarantee no one would recognize you. This normally works for AB or DL reasons for wearing.
Another cheap option if you don't want go out or have access to transportation is making one using a towel and cutting a garbage bag in half and taping the bag over the towel. It would be like a cloth diaper with the bag acting like a diaper cover. You just need large safety pins and a quick google of how to fold a cloth diaper and you should be good. I don't recommend this for heavy wetting but it is good if you want a crinkle or bulk as your main reason for wearing.
If you have some disposable income and would you can check online sites like bambino and they normally offer a sample pack with different types for you to try and find what you prefer if you don't already know.