sorry, 28€ can't work. At least not for the entrepreneur. Of course, it's possible that he just slaps the thing (Terrace) together, then 28€ might even be too much (for you). But without accusing the provider of anything (bad work), I rather believe in faulty calculation (or maybe undeclared work). Many craftsmen without a commercial background tend to make their calculations too optimistic. How is he supposed to finance necessary tools, build reserves, factor in risks (something can always go wrong that he has to pay for himself), payment defaults, contribute to retirement provisions, pay office costs, etc. The time he spends in the office must also be calculated (no one does the paperwork for free, and that reduces the quoted price by at least 15-20%). For all the reasons mentioned above, I don't think this is a good idea (for the entrepreneur). Currently, mEA probably 45-50€ will be necessary. No idea why, somehow I keep getting more left-wing and radical.