Is the SIM CARD SLOT and the slot that you would use to add memory the same. I intend to buy an unlocked Samsung Note9. It comes with 128 0r 512. I would like to get the cheaper one and add the memory card I have in my current phone. As an alternative, can I get a SIM card with extra memory?
a SIM does not add memory it just grants access to the Cell Networks (GSM and LTE)
an micro SD-Card can add memory (in my option this best used for media like music, photos, videos, documents)
both the SIM and Micro SD Card install in the same tray on most phones. (BYOD SIM card can be found here)
Make sure you are buying the North American (US) Factory unlock Note 9 (model SM-G965U1) as it the only model supported by Republic (no international or carrier unlocked models) (How to Find a Compatible Unlocked Phone)