You want to bring everyone together to celebrate the new place, but the total bill can sting when it hits all at once. Sunday afternoon is your best friend here, as you skip the heavy dinner costs and focus on snacks and drinks.
Planning early gives you the edge. Break your $600 budget into a timeline so you aren't paying for everything the week of the party.
Remember that the 0% intro window is a deadline, not a gift. If you haven't paid off the $600 by the end of the 18 months, any remaining balance will start accruing interest at the standard rate.