In this market, you are wise to seek the services of an experienced buyer's agent. Builders are luring buyers with all kinds of incentives, prices are soft, inventory is dramatically high, all of which points to the buyer being in the driver's seat.
The highest profit margin in new homes is the upgrades. Not only should you be able to negotiate an extraordinary price by using a buyer's agent, you should also be able to negotiate free upgrades and a few other concessions such as paid HOA dues for a year, interest-rate buy downs -- which will lower your payments for at least two to three years, in addition to the builder paying your closing costs.
Your buyer's agent should supply you with comparable sales in the neighborhood, including pending sales (which are indicative of the direction value is moving) and expired listings ( which are indicative of overpriced listings). You should look at the last 15 months of Trends for that development and neighborhood to determine the average price per square foot, the median sales price, the average days on market, the number of sold homes vs. active vs. pending. Pay close attention to the number of months of inventory. Last month, there were 15 months of inventory on the market in Sacramento. This means it would take 15 months to sell everything that is listed, which is an awfully long time.
As the home buying columnist at About.com, which is owned by The New York Times, I have written several articles that may help you with your search. Go to google and in the search box enter "Buying Brand New Homes From Builders," and my article will show up at the top.
I work at the downtown office of Lyon Real Estate, which covers all surrounding neighborhoods of downtown, and I live in Land Park. If you questions about the content in any of those articles, feel free to call or e-mail me directly.
However, as another poster noted in this thread, since you have already made contact with the builder, you might not be in a position to bring in a buyer's agent. Builders do expect buyer's agents to register their buyers. So this could cause a glitch for you. On the other hand, most builders are pretty desperate right now, sitting on a ton of spec homes that aren't moving, so they might not be too pushy about enforcing those types of self-imposed rules. Good luck to you.
We jump all over our peers when they blatantly self promote while adding little or no value in their answer to the question.
What we saw here, amongst five posters before you, were good answers, including the horn toot. The poster who received best answer by the questioner held her horn tooting off until after 4 paragraphs of great advice. - Even then it was subtle enough for me. - And I am a rather harsh critic of some of the self promoters.
Have you ever heard horror stories from someone you know who purchased a new home? No one interpreted the purchase agreement for them, they were not informed of certain upgrades available to them, no one was their advocate with regard to making repairs before and after the sale...the list goes on.
Now if you have identified a development already, there is a chance that they will try to deny you your own representation. Most builders in this area require that your agent be present with you during your first visit to the property, and fill out some "registration" paperwork in order for your agent to be compensated by the builder. If you do feel an agent would assist you in your purchase, you may not want to waste time finding one you like.
The listing agent is put in a difficult position by representing the buyer and the seller. There is no way they can truly represent the best interest of both parties with conflicting interests.
Congratulations on finding your property. New developments are usually marketed through their sales staff (as you mentioned). When they are closing out their development and have a just a few left and/or when they haven't been successful marketing it themselves is when they would generally find a realtor to "list" the property. I'm just wondering what you mean by "marketing agent", I'm assuming that they have a listing agent.
The advantages of using a buyer's agent are many especially in most cases the services are provided to you, the buyer for free. Finding the property is generally the easy part of the buying process, the rest that follow are complex and time consuming. You are hiring a professional to represent you and your best interest. I would find a realtor to further discuss these properties with them. Won't cost you a dime to explore the possibility! Good luck!