Hey Shara,
If you mean you want to purchase those domain names and 301 redirect them there will only be value in that if they have already accrued link equity. Otherwise if there's nothing there and it is a new domain name it will never be indexed if you are redirecting.
If you mean you want to buy a domain name and build a doorway page to a specific page on your site this has been expressly frowned upon by Google for years.
Either way it's not the worthwhile usage of resources or time unless the domain already has link equity that can be transferred to your site. And you would also have to actually have legit pages on the site to make it worth the effort.
-Mike