A combined heat and power plant usually runs on gas. Now the question is whether you want your basement to be cooler after the combined heat and power plant phase ends, or if you want to retrofit an underfloor heating system. And of course, one can also speculate about the time frame. At some point between 10 and 25 years, no combined heat and power plant will be running anymore. For a basement, this is probably acceptable to dig up again after about 15 years...
Another perspective would be the financial one. You say 2700,-€ for the underfloor heating system. How much does one square meter of your living space cost you exactly, and how many square meters would the radiators cover or block? I guess there is a net gain through the underfloor heating...
What are the advantages and disadvantages of underfloor heating and what are those of radiators?
I don’t quite understand the question now. Have you been following along the last six pages? Everything was mentioned...