"To buy a membership" means to pay for a subscription or access to a particular group, organization, or service, granting you special privileges or benefits that non-members don't have. Full definition
It is, therefore, asked of you to gather enough information about the company's background before buying a membership. (policybazaar.com)
But it's still comparable to the price of buying a membership separately and comes with a host of other elite benefits that I've already discussed. (travelcodex.com)
Save your dating dollars for dating, not for buying membership in an expensive site that doesn't get results. (articlesfactory.com)