Here are some answers to your questions:
Q1 Postage Costs - Mike sends these out in a regular envelope (letter size), so the postage is like $1.30 or thereabouts. Mike tells me he can put 4 sheets of the 1/72 zim in a single envelope for the same postage, as it is just folder up paper. So yes, postage is really next to nothing.
Q1a Zimmerit Pattern - 1/72 isn't Mike's normal build scale at all, so he is finding it a bit difficult to fit the kits. Mike makes models for a living and runs Monroe Perdu on the side. However, he usually works with much much bigger items, so this is really pushing his eyesight! Hence, the drinking martinis to ease the pain and improve the vision! LOL Seriously, as to the Alkett zim pattern if you fold the edge harder you will get a sharper line. It is really up to the modeller but the pieces are all there. The Stug zim set is scaled down from his bigger sets. Below is a link to his 1/48 rendition of the Alkett and MiAG zim patterns, which will give you an idea of what the 1/72 sets (yes, Mike is producing both patterns for us!) will have (it includes the side skirts!).
Q2 Price for Zimmerit sets - Mike has told me that the price point will be around $10 USD per set, which is a pretty good deal I think given the quality and ease of use.
Hope this answers your questions.