The answer to this question largely depends on your individual shooting needs and preferences. For example, if you mainly shoot at targets that are close to you, a peep is likely a more cost-effective option than a scope. Conversely, if you primarily shoot at targets that are far away, a scope may be a better investment.
Additionally, it's important to consider the type of rifle you're using. A scope is typically more appropriate for weapons with longer barrels (i.e., rifles), while a peep can be used on shorter firearms as well. And finally, take into account your shooting environment – peeps are less visible in low-light conditions than scopes, but can be harder to use in cold weather.