Deltarune creator Toby Fox has published a blog following the release of its second chapter which details the plans for the continuation of its story. Here Fox notes that Chapters 3-5 will release simultaneously and they will not be free to download, unlike the first two chapters. The specific pricing for these chapters was not revealed, but it was stated that the package as a whole will cost more than Undertale. Just for reference, Undertale's price varies across platforms, but it's currently retailing for £12.49 on Xbox and £6.99 on PC.
Within the blog, Fox said: "My next goal is to complete Chapters 3, 4 and 5 for next time. Then, at that time I will ask for people to buy the game, at the price of the first 5 chapters (including 1 and 2). I don't know the price yet, but it's definitely going to cost more than UNDERTALE."
Regarding the game's recent second chapter, he also added: "We gained a lot of experience working on this chapter. I believe it's the biggest chapter in the entire game in many ways. The cutscene count is the largest, the story involves many characters, and there are many other aspects that made it a challenging chapter. For next time, I think if we can expand the team a little more, then things will really kick off... maybe."