In the past I did a little research on the cost of living in Finland, I can t see that the mentioned costs are very different. (Don t know about the certification costs, but it would be stupid if they are too high).And as far as I understand Germany has much higher wages then Finland.

Lets do a little math, hourly wage is about 30€, pretty much the same as in Germany, renting from Finavia would be not more than 200€/sqm and you need max, 20sqm, and I m pretty sure that you can find a good deal with Finavia at the moment since they need money and no one can sell enough bags or beer to make a good living.

Open your shop 15 hours a day means that that you have costs of less then 20.000€, so you need to perform approx 300 tests a month to cover your costs - 10 a day if you charge 65€ - if I perform 1000 tests a month - and that would be a low number I assume - I would turnover about 50.000€, minus the 21000€ for the testcenter, labour and materials. so I have another 29000€ I need to pay taxes on - not a bad income.

In Germany many of the "testcenters" are just old ambulance cars, parked in the street - so no rent there. Maybe I do so at Helsinki airport , drive by testing it is called, give me a call and I test you in 2 minutes.