1 1/2 years ago I posted on my blog where to buy affordable Vit-C. This ebay-seller is very friendly and he assured me that he ships worldwide. The seller is still active. Reasonable price and shipping: http://caffenol.blogspot.de/2011/06/...de-seller.html
Vit-C: many supermarkets in Germany, every pharmacy, 2 - 3 Eur/100g
Washing soda waterfree (brand: Heitmann) I get at the local supermarket in Germany, 1 Eur/500g. Also at the "DM-Markt". In France there is sold a "soude cristeaux" containing 50 % water in supermarkets.
Instant coffee: every Aldi, Lidl, supermarket in Germany. Buy the cheapest. Here 3.60 Eur/200g
Best - Reinhold