October goes fast, and the best props disappear from store shelves before the month even starts. Getting your decorations early means you avoid the last-minute scramble and actually have time to set up that spooky scene you have in mind.
A budget of $350 covers the basics for a solid garage setup. By planning your spending now, you can lock in your theme and spread the cost out so it doesn't wreck your monthly cash flow.
The 0% interest window is a deadline, not free money. If you have any balance left after 18 months, the bank will start charging you regular interest on what you still owe.