Step 1: Go to
www.yycdeals.com and go to the deals map. Choose under $400, and see what comes up. One option is San Diego, which is a pretty good place for a summer vacation.
Step 2: Go to
www.redweek.com and type in San Diego, choose San Diego and area. Then go through the different choices and pick something that works for you and is a reasonable price.
As an example, June 18-25 is $439 to San Diego, and then 1 week rental of a two bedroom at the Grand Pacific Palisades Resort for $1200
http://www.redweek.com/posting/R350107
Total comes to $2956 for 4 flights and a week stay. You'd have a kitchen/BBQ, so you could probably stretch the last $1000 cover food/entertainment.
Spend a couple of days by the pool, some time at the beach, maybe splurge for legoland for a day.
Step 3: Profit!