Does size Doesn't Matter?

[Outer_net]

I cant believe shopify gurus advise that size does not matter when it comes to shipping and that the only important thing is weight. This was from an advisor earlier today.

Anyway here is proof that it very much does matter

SHIPMENT DETAILS 

Package A - 120 cm x 120 cm x 12 cm  at 12 kg weight - via UPS shipping cost Germany > UK 171.83 Euros

Package 8 - 60 cm x 12 x 12 at 1 kg weight  - via UPS shipping cost Germany > UK 24.51  Euros

That leaves a difference of 147.32 euros

I DONT WANTO AND CANT AFFORD TO USE AN APP TO SOLVE THIS

I know go and save up and come back to shopify when the budget is enough - Shouldn't we be able to do this as is ? 

Has anyone used or got access to a private app that can accomplish this?

All the Best

[Outer_net]

Just for comparison the different packages with the same weight 12 kg now a 92 Euros difference