Another batch of PSPi Zero boards is going up in about 20 minutes. The initial demand should be waning, so I expect these to stay in stock quite a bit longer than the first batches.
https://othermod.com/product/pspi-zero/
The PSPi boards are back in stock.
https://othermod.com/product/pspi-zero/
If you miss this one and want a notification for the next batch, you can subscribe to get an email notification on the product page