Today I did some research on possible legal aspects regarding the sale of products that contain electrical/electronic components. To my regret, there are a lot of requirements and regulations here in the EU that have to be met and complied with in order for a sale to be permitted at all (CE & RoHS labelling etc.).
It looks like I won't be able to sell my #NeXTcube mini as a whole. That could cause me huge problems. So I think I will sell just the case itself. That is a great pity.