Latest update - had a potential cruise mate from here on the site, but that fell through at the last minute. The options out of Port Canaveral have gone up in price, but there is an NCL cruise out of Miami leaving on Friday, February 4 available for only about $230/person (including all taxes).
I could also potentially consider a 4-night next week, also out of Miami on the Carnival Imagination, 2-7-2/11, that is available for about $245/person.
There are also some relatively good deals for the weekend of February 25 as well - not quite as good as this coming weekend, but that weekend is a possibility too.
I know it's last minute, but here's an idea: obviously getting to Miami last minute could be expensive for flights...I have plenty of frequent flyer miles and could book flights if you took care of the cruise cost. Contact me if you're interested, and I can look up flights from where you are to see if anything is available. Either post a reply on here or email me directly at firstname.lastname@example.org
Hope we can come up with something!