Costa Rica in May is quiet, green, and alive. The rainy season, or green season, starts up, which means afternoon showers wash the dust off the canopy, the forests turn a blinding shade of emerald, and the wildlife gets active. You fly in right as the peak dry-season crowds leave and resort prices drop.
A typical trip runs about $3200 for flights, stays, and getting around. Spreading that cost out over time helps you lock in those lower May rates without draining your bank account all at once.
Remember that the 0% intro window is a strict deadline, not free money. If you still carry a balance when those 18 months end, the remaining amount will start accruing high interest charges fast.