That's absolutely ridiculously expensive, obviously.
You can outright buy tokens for 20 gold coins per Token - that makes for a total cost of 10,000 gold coins. The Bunny Recipe Book will cost you 500 Tokens - so you'll need to scrape those together. The item description says it all: 'Patterns and Diagrams to help you be the best bunny girl on the block.' It's at this exchange counter you'll find the Bunny Suit Recipe Book, also known in the game menu as Down the Rabbithole. Inside the Casino you can swap your casino tokens at the exchange counter.