Where to buy Maltodextrin and/or Dextrose?

[SS1]

Does anyone know where I can buy maltodextrin and dextrose? I use these as a carb source for my post-workout shake after the gym. Actually, I normally use Waxy Maize Starch but this must be even mode difficult to find here. I think the beforementioned ingredients are used for other stuff too, such as brewing beer and other food industry things, so they should be available somewhere.

I have checked all the supplement stores, but none of them have these available. I never buy any ready pwo-shakes or "magic muscle building formulas", but I prefer to build my own mixes from pure raw ingrendients. In Europe this is easy with MyProtein, Bulk Powders etc.. and a lot cheaper too!

But anyways if you know where I can get these two please let me know, and how much they roughly cost per kg? Thanks.