Test kits made by TIB Molbiol cost EUR 2.50 per patient. One kit can be used for 96 patients (or up to twice that number if diluted), so cost of work is spread over quite a few people. Their estimate for a reasonable price is EUR 10.00 including work.
Source (German): https://www.tagesspiegel.de/berlin/tib-molbiol-berliner-firm...