Buy something from China in semi-bulk (e.g., 6–12x) on Alibaba / AliExpress and resell for profit from the US.
Even on very small purchases, like $3 phone cases, people are willing to pay 2-3x the price to be able to get them quickly from someone shipping from inside the US. While it's not _highly_ profitable after fees, I think you could automate and outsource most / all of the work.
Not sure if this totally aligns with what you and your friend are doing, but just an idea I've been wanting to try lately.
Even on very small purchases, like $3 phone cases, people are willing to pay 2-3x the price to be able to get them quickly from someone shipping from inside the US. While it's not _highly_ profitable after fees, I think you could automate and outsource most / all of the work.
Not sure if this totally aligns with what you and your friend are doing, but just an idea I've been wanting to try lately.