>>7745504>160$ +tax +tip +shipping +trackingTax goes without saying, you get taxed on pretty much any purchase. Where the hell are you shopping that you need to tip them? Tracking isn't mandatory unless you decide to pay for a shipping method that has it.
And as for shipping, if you weren't aware, HMM Zoids boxes are fucking massive. You typically need to size up one from your typical thinking--a built HG-sized Zoid comes in a MG-sized box, a MG-sized Zoid comes in a...well, not PG-sized, but a damn big box. The boxes are big because HMMs are very complex/layered kits with tons of tiny parts, and that equals tons of sprues. And that also kinda answers your question about why the base cost is so high.
They're an expensive thing to get into, but also very satisfying.