Allow a pay-as-much-as-you-want for a subscription.

Give the option to subscribe from $1 or 1€, up until as much as you want, as basic or extra support for the streamers
The emotes and benefits of being a subcriber would unlock each time you pass the threshold of a "normal" sub price

This would give the option to support, even so slightly, your favorite streamers or friends. Or to give a little more every month as extra bonus