Are you silver with either UA (premier) or US?

If so both NW and DL should just do a free status match for you. No need to go through AA first or buy a NW package.

EDIT: If you are going to status match, don't do it now. Any status matches this early in the year will expire 2/09. You need to wait until you're closer to your departure date to do it. Status matches are also only once in a lifetime. Don't waste it if you think you'll need it again in the future. 25-50% bonus miles for one spring break trip aren't worth using it up.

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BTW, I think in general its WAY too early to be buying spring break tickets now. I guess its your gamble to make, but in a normal market tickets would most likely get cheaper a little closer to your departure date. Without knowing what will happen with oil in the next 9 months, prices may go down or they may not.