That's not necessarily shady, stores don't know how big and heavy boxes are until they get them from manufacturers, so shipping estimates may need to be revised. These stores aren't megacorps like Amazon that can just eat the extra fees. I don't remember seeing any shipping cost upfront with KGHobby. I only pay deposits, I assume it's different when you pay the whole amount right away?
In some cases you end up paying more with stores that include shipping in the price because the box ends up smaller than anticipated. While it's great to know the full price right away, you don't always save money that way. I mix and match my orders, some from shops with shipping included, some without. Sometimes I save money, sometimes I pay more.