If the baby flies in your lap that is 5 tickets. And here is a picture of the matrix of rock bottom prices in
September of this year $600 = $3k for the 5 of you. If you push browse fare history you can see what the average fair is. In May it's around $500-600/per person.
So prices from Norfolk is definitely doable in the $600 range, and if you are paying attention, get on flight alerts you'll be able to hit under $500 like my mom, grandma did. I have flight alerts on my email to help me catch perfect deals like the $422. Also it's not a good idea to try to ride specific airlines. This makes it less likely you'll catch a good deal.
Stay at the ghetto
pagoda hotel for $150/night. NOT as nice as hale koa but a good deal. Get the 2 room with kitchen, and bam, I've saved you a bunch of money. Eat breakfast and lunch there, unless you are with family. Invite family over to hotel and eat in the room. Shop at commisary when you are in hawaii because I just got you a hotel with kitchenette. It's walking distance to ala moana, walmart, and the beach. Depending on where your family lives it's not great, but if you were going to stay at hale koa it's the same thing.
Next step priceline your car. Use this website
bidding for travel to get an idea of what to pay. I think $30/day should get you a minivan. So $250/8 days. There half the price. Or find a great budget coupon, right now my roomie is renting a car for 14 days for $200 total! Some coupon deals are better than priceline.
I've trimmed a substantial amount from your budget for the trip.
I tend to agree about going alone. Last time I went home I went alone. DH didn't want to spend that much going with me over Christmas when my mom had surgery. Turns out it was the right move.
Less than a month after I got back, my grandfather died and I went right back to hawaii. And yes I had to go, my mom was a single parent for the first 10 years of my life and my grandparents really did help to raise me. And DH went with me because I was quite sad and he knew my grandfather better than his own, who had also recently died.