I read the manual and it says that Price is a VARS (var*) and to output I do %f.
But I will try another values. I know that I had such a problem in the past and it was of the wrong usage of printf. :-)

I think I have a deep misunderstanding. I get no output at all. Shouldn't I see current price line after line?
This is from the manual:

"%[flags][width][.precision]f" for var or double variables with decimals.