My advice would be to spend what you can afford. If it is within reason to spend 4 grand on the dress of your dreams than go for it!
I set my budget for $1000.00 but ended up spending twice as much as that, knowing full well that I would have to pull in some serious overtime to be able to pay it off when the time came. I did, and it was SOOOO worth it for me.
I don't think that there is anything wrong with spending a small fortune on your wedding dress provided that you won't go into serious debt for something that you will wear for one day (or two if you are having an AHR).
I have watched a bride walk down the aisle in a dress that cost no more than $100.00 and on the other side of the spectrum, been to a wedding where the gown cost over $10,000.00 (and believe me, she could afford it!)... Anyway, I guess what I am trying to say is that if it is within your budget to get the Jim Hjelm that you have fallen in love with...then there is no reason to have to justify spending that money on the dress of your dreams!