I'd recommend a Royal Caribbean Cruise. We paid about $4000 6 years ago for a 7 night cruise. We got a balcony suite though. You don't have to get that type of room. They have a variety of packages to choose from too.
We are going to Florida in a couple weeks together and the plane tickets will be 400 for the both of us. We will be staying with the in laws while there so we don't have to pay for a hotel or anything. I'm grateful that I have wonderful in laws!!!