A pop-up camper is the cheapest way into camping with a real bed, but the cheap sticker hides the real math. You'll pay for storage if you don't use it, repairs if you stored it badly, and a tow vehicle that drinks more gas the heavier the trailer gets. Most owners only get 8 to 12 weekends out of it a year, so the per-use number matters more than the purchase price.
Late autumn is when sellers want the unit gone before storage fees start in November. That softens the price on the trailer itself, but it does nothing for you on the add-ons: a new battery, a cover, maybe a hitch lock. The play is to separate the negotiation from the financing, and use a card window for the smaller stack you can clear fast.
The 0% period is a runway, not a discount. If the balance is still on the card when the 18 months end, the standard rate kicks in on whatever's left, and you'll owe interest back to day one. Set a payoff date now and autopay it.