Hi :)
First, are you sure to use only one survey in the pledge manager (and not a new survey for your friend) ?
In the Shipping part of the
Kickstarter page, I see that Mexico is in AREA 5 (Central America) and there is this sentence :
Would you like to pledge for multiple copies?
Each copy purchased includes all unlocked Stretch Goals. For areas 1, 2 and 3, shipping costs after the first pledge (up to a maximum of 7) are halved! We are still looking for solutions to get some discount for multiple copies for areas 4 and 5 as well (hopefully by the end of the campaign).
So, I don't know if the price is correct/up to date.
For the waves, please read the
update #70 :
As indicated in our last update, it will allow those of you who so wish:
Request to receive their already available rewards (Base Box and game accessories) in wave "1.5" with a delivery scheduled in September/October 2018. There will be an additional shipping cost but it will be no more than if you’d have originally chosen delivery in two waves last November.
Add Base boxes (limited to surplus production available stocks) and/or expansions to your contribution that will be delivered in wave 2.
Add game accessories to your contribution: they will be delivered in wave 2. They can be delivered in wave 1.5 but only for contributors requesting to receive their Base box in wave 1.5. Note: If you have already received content in wave 1, it will unfortunately not be possible to receive delivery in wave 1.5 for game accessories.
With the opening of our online store being postponed until 2019, the reopening of the Pledge Manager will also allow those who did not participate in the campaign to purchase a Base box, expansions and/or game accessories. These production surplus copies will be proposed within the limit of available quantities, with a delivery in wave 2.
Firebird 
DV, OG, LG --- 
SI, [CD+SI] --- 
Histoire, Pénitence, Funéraille --- 
[SI+TS]