Charleston in the spring is hard to beat. Going midweek lets you actually get a table at the best seafood spots on King Street and walk the historic neighborhoods without melting in the southern humidity. You get the pastel houses, the coastal breezes, and the slower pace before the summer rush hits.
A typical trip runs about $2200 for flights, a good place to stay, and a few nice dinners. Dropping that all at once can sting, so spreading it out over time makes it a lot easier to swallow.
That intro window is a deadline, not free money. If you still have a balance left when those 18 months are up, standard interest kicks in on what you owe.