Amazon has dropped their prices on a bunch of SanDisk Memory products. Finishes at 7PM today. Always pay in US currency to get best rates.
Further $5 off $25 purchases using the Amazon Assistant.
256GB, Even the usual Shopping Square listing has it for $200 - 10% = $180. Cheapest price ever according to Camelx3.
128GB $33.64 USD (~$44.13 AUD) , Cheapest ever via Camelx3, $2 or $7 cheaper than the last Amazon deal although that looks different and I'm not sure if the OP included the $5 off Amazon price.
64GB $20.30 USD (~$26.64 AUD), Cheapest ever via Camelx3. Appears to been cheaper before but current cheapest.
200GB ends up being $55.13 USD (~$72.30 AUD). Better off getting it from the PC Byte Deal.
256gb / $90 USD = 2.84gb per $
128gb / $28.50 USD = 4.49gb per $
64gb / $14 USD = 4.57gb per $
200gb / $50 USD = 4gb per $
Higher gb per $ equals better financially or economically because you get more micro sd card storage per dollar.
Doesn't take into account other factors though such as shipping, import duty tax and USD to AUD conversion rates.
Imho 128gb is the best option money wise and space wise but the tiny tiny extra premium for the 200gb is well worth it.
256gb is still quite expensive comparatively.
64gb is the best bang for buck price wise.