In my opinion, the special offer idea would work well with offering yearly membership subscriptions. This way, one could offer more expensive physical goods like T-Shirts, mugs (…) and get the costs covered.
This would also be a good way to convert existing patrons to paying for a full year upfront.
Of course, a yearly payment option is currently not available. But here is hope that this will change in the not so distant future. I think, this would be great for everyone involved.