A small utility trailer is one of those purchases that sounds simple until you start adding up what it actually costs to own. You pay for the trailer, of course, but you also pay for the registration, the lights, the hitch if your truck doesn't already have one, and the lock you really should buy on day one. Insurance is usually bundled with your tow vehicle, but check before you assume. Altogether, the realistic first-year outlay is the trailer price plus a few hundred dollars in setup.
Trailer prices are softest in late winter and early spring, before landscapers, contractors, and weekend haulers all show up at once. If you want leverage on price, shop now and pick up early. Negotiating the sticker and financing the purchase are two separate problems, and the rest of this plan keeps them that way.
The intro window is a deadline, not a gift. If a balance is still on the card when the 15 months are up, the regular APR applies to whatever is left, and that rate is the part that actually costs money. Treat month 15 as a hard cutoff, pay the balance to zero before it, and the trailer plus its setup ends up costing roughly what you planned.