Bear in mind as well that the necklaces will be available for each set of whaleship missions, while the other items may not (the last round of Mission 2 maps, for instance, only had the necklaces in the shop). Stock up on the consumables as needed first. Later mission maps will award more medals which makes the necklaces easier to obtain so don't stress it too much now.

Oh, and those second affection gifts will take you to 90%, not 60%.

When will we be able to exchange 3* and above for 2nd affection items currency?