Its a tough one..
I think you will make the right decision in the end. I hate that feeling of wanting something so bad and being held back then to watch it snapped up by someone else. I am with you on the moving, i hate it so much, not only moving all the furnishings etc but moving the kids from there home. When i was growing up we moved many times, my parents bought run down business's and built them up then sold usually within 3 years, so we never stayed put for long but thankfully we stayed in the same area.
Personally i would do it, you can make a home for your family anywhere and you will kick yourself if another opportunity arises and you are not in a position to take it.

Good luck with it all.