Dear Fed Up,
I feel your pain and its no different than the pain many of our sellers are also feeling. Putting a home you've not only invested your money in, but also one in which you've made upgrades and maintained beautifully, can be emotionally and financially tough right now.
There are many times I have to tell sellers that while their home may be wonderful, they will most likely will not realize the return on their investment that they might have several years ago. Due to the state of the economy and huge inventory, house prices are significantly down. Add to that the fact that lending institutions across the board are being a lot more careful with the money, and rising values are still some time away.
Appraisals in this area are routinely being reviewed and picked apart by loan underwriters. While an appraiser may believe a particular home should be valued higher than the value given, if she can't find comparables to support that value, she can't put a higher value on the appraisal. The appraiser answers to the loan underwriter, who answers to the higher-ups at the lending institutions. This is regulation we have not seen in quite some time.
Keeping in mind the volume of new construction in this area by builders like those you mention and knowing how many of those homes are currently in some sort of distressed sale situation, its not surprising that your home is being compared to those. That's about all appraisers have to used as comparable home sales.
If you can, you might consider staying in your home for now. The market will rebound, inventory will decrease and prices/values will start leveling off and eventually go back up. I tell folks all the time, if you don't have to sell now, don't. And if you do need to sell now, at least you will pay less than you might have a few years ago for your new home.