I've made a $20 membership on Patreon right before I took commissions there, thought I would do the same here.
The $20 plan is for people who want to get a commission later this month. I should have done it earlier but I'm a stupid boy.
Instead of the 20% discount from the $15 plan, you get a 25% discount for commissions.
Of course there's no need to pay for the plan if you don't want to, completely up to you!