Thanks for all of the in-depth details, in this thread and others. Very informative, and probably more than anyone expected you to divulge.
The numbers seem reasonable and about what I expected, at least up until the distributor charge. 25% (minus a bit for shipping, although I expect you can get the prices per unit down pretty low once you start shipping 100 of them at once) seems high for online distributors. And if buyers won't pay anything extra to get it from a distributor instead of getting it from your shop, what's the point of having distributors at all? Especially when you give up 100 EUR per-unit when doing so.
I do wonder, since you said you'd match the distributor price at your shop, does this mean you will make distributors sign an agreement that they will only sell at your approved prices? If not, does that mean someone can get a distributor agreement and buy a hundred units from you then sell them on eBay for 449 EUR instead of 499? There'd be some people who would buy this units instead of the distributor ones, but they'd also sell out pretty quickly.