An ExpressionEngine 2.x plug-in which can be used with the Link Vault module to enforce a download allowance.
{exp:link_vault_allowance member_id="1"} {if allowed}You have sufficient allowance to download this item{/if} {allowance_lifetime_used} {allowance_remaining} {allowance_period} {allowance_period_cap} {allowance_period_remaining} {/exp:link_vault_allowance}