The biggest misconception we have seen when it comes to subscriptions to this point is that the subscription will add additional digital game content to your account. Let's clear that up! Subscriptions do not add additional digital game content to your account.
Unlocking official digital content outside the free Basic Rules/ SRD is done through one-time purchases.
D&D Beyond subscriptions are intended to enhance a player's use of the toolset. The low price points are indicators of this. The idea is that a subscription is not a hard requirement to use D&D Beyond - many players will be able to do everything they want to do with a free account. The subscription tiers are meant to provide additional value that some players will want.