You pose a very good question. And you have some great answers.
My suggestions would be:
1. Talk with a REaltor that knows local market trends and values and get a realistic idea of your home's current market value.
2. I believe that you measure twice and cut once. That means analyzing the entire move. Figure out how much you would owe (or net) after the sale. Then figure out what you could buy, and how much that would cost.
3. There are generally more people that can afford less expensive homes, and fewer people that can afford expensive homes. That means when trading up, there will be fewer qualified buyers. So in most cases more expensive homes decline more in value.
That means that all things being equal, you may lose a little when you sell, but you'll save more when in buy...if you are planning to buy and hold.