While I'm all for saving costs, I would be shocked if mixing your own inject-able medicine either weekly (with the chance of making a mistake in dosage or sterility) or too such a high degree of sterility that you can confidentally store several doses is not worth the $200 return flight every two years. Maybe I'm overestimating the risks but it still seems like a small saving for it.

Realistically the cost of semiglutide in generic form means you could fly return every 90 days (personal import restriction for perscription meds) and still save $1000 every 3 months (3x$500 monthly - return flight - generic cost).