When Jens Bergensten joined Mojang (to work on Scrolls), Minecraft was quite advanced and already had the nether and red stone. Notch did not rely on any store and was using his personal paypal account that got blocked due to an anomalous amount of transactions.
https://minecraft.fandom.com/wiki/Java_Edition_Alpha_v1.2.0
https://blog.omniarchive.uk/post/1096322756/working-on-a-fri...