Before you do any surveys, I'd strongly recommend talking to 5-7 prospective customers first - either in person or on a phone/video call. During that, I'd ask questions to learn what you're competing against - what other educational toys would they consider instead of yours? What would yours need to do to be different enough for them to buy? How much are they willing to pay? Once you've talked to a handful of folks, then it's OK to do a broader survey with a tool like SurveyMonkey Audience: https://www.surveymonkey.com/mp/audience/. You can think of the qualitative research as a way of informing what options you present to survey takers on the pricing question.