In January, IM PLAYIN asked the question 'will Project Spark actually be free?'. Now that they've had a chance to play the beta and have got to grips with the creating process as well as the micro-transactions feature, they've revisited the question.
"In fairness to the game, there is an absolute multitude of things that you can do and create without having to spend any money. You can pretty much build whatever you can imagine in the free game, (providing that what you’re imagining sticks to the free content), and you can even play other people’s created content. If, however, you’re like me and you have much grander visions than a game world covered in grassy / snowy / sandy mountains surrounded by grassy / snowy / sandy fields, you’ll probably be itching to purchase some of the added content"