I know the cost section might put a lot of users off the idea of doing this, but ignore the total cost, because the total cost is likely not going to to be anywhere near that. Since, most of these items, people already have especially if they're a home owner. For example, I have millions of washers/screws (including the size required), I have a sledge, gloves, duct tape, hot glue gun, and a micro fibre cloth. That has already reduced the price by 35+ euros based on the OP's pricing. Although, I bet I have a tonne of other stuff in storage that can either be substituted to a degree or already have. For example, the stickers could potentially be substituted.

This is just going to draw more attention to yourself, since whoever is snooping in your bins, will now be asking why your feeding washers to your baby. Nah, but in all seriousness that's a good idea, even some of the lowly thief's aren't going through diapers.