updates

js/model/inventory_article.js

@@ -46,6 +46,10 @@ InventoryArticle.prototype = {
     },
     get Sale() {
         return this.Sold * this.article.PortionPrice;
+    },
+    get StepSize() {
+        singlePack = this.article.Portions == 1;
+        return singlePack ? 1 :  0.05;
     }
 };