You can calculate the total price of the order now and on Wednesday and see for yourself which the cheapest option is.
- Add the products you want to buy to your shopping cart.
- Select "Economy International" as your shipping method and write down the shipping costs and price of the products.
That's all the info you need. I'll give an example where I've only added a tub of Barrister and Mann Seville to my shopping cart ($15.99) and selected "Economy International" as the shipping method ($1.83).
1) 24-26 November: 70% discount on economy international shipping
After adding Seville to my shopping cart, I can see that the shipping costs are $1.83. There's currently a 70% discount on economy international shipping which means we only pay 30% of the normal shipping costs. That $1.83 is 30%.
Shipping costs:
-> $1.83 = 30%
-> $1.83 / 30 = 30% / 30
-> $0.061 = 1%
Total price:
1x Barrister and Mann Seville: $15.99
1x shipping costs (70% discount): $1.83
= $17.82
2) 27 November: 10% discount on all products (minus a few exceptions)
On Wednesday you'll pay the full price for the shipping costs, which means 100%. We already know from step 1 that 1% = $0.061.
Shipping costs:
-> $0.061 x 100 = 1% x 100
-> $6.1 = 100%
10% discount on products:
-> $15.99 x 0.9 (=90%) = $14.39
Total price:
1x Barrister and Mann Seville (10% discount): $14.39
1x shipping costs: $6.1
= $20.49