Hosting an engagement party in your backyard keeps things relaxed, but popular food trucks book out fast. You need to lock in your caterer at least four months ahead, which means dropping a deposit long before guests arrive.
A typical setup costs around $3,000. Spacing out that bill instead of taking a single heavy hit to your checking account gives you breathing room while you sort out the rest of the details.
Keep in mind that an intro window is a fixed deadline, not free money. If you still have a balance on your card after 15 months, the standard interest rate kicks in and makes whatever is left much more expensive.