LamaPoll is a survey tool from Germany, for very secure (ISO 27001) surveys.
LamaPolls free plan can be used for up to 50 respondents with unlimited questions. After that, the basic plan with up to 500 respondents is available for €49 monthly. More plans exceeding that are available too.
For students, the basic plan is available for up to 3 months for free.
Read more on the pricing page of the service.