Check the meal replacement bar thread I made. Just mix all of that together and eat it. Cheap and effective for bulking. You can get an easy 1000 calories from quality ingredients for like $1.60 investment. Now if you're shooting for 3000+ calories in a day, an easy 1000 calories is welcome.
I'm going to start trying to eat 1000 calories worth of those meal replacement bars (which would be half a batch) every day.