Hello Sigil and thanks for your question.
As the others have noted, in the past, here in California, new home sales were so brisk that developers did not need to negotiate on the price and did not pay referral or buyer's commission to any agents who sent buyers to a new home development. Recently, things have changed, and for the past two years, developers have offered to provide Realtors who brought in clients a small referral fee, which varies from developer to developer from amounts as low as 1 percent to as much as 4 percent. While most are offering to pay a commission to the buyer's agent, the amount of the price that can be negotiated will also vary from developer to developer and housing complex to housing complex. At the beginning of a sales release, the amount that can be negotiated is likely to be less than it would be at the end of the release or new the end of the project's sales cycle--much like a car, you'll pay more at the start of the model year and less at the end.
Recently, developers have been negotiating with the banks holding their construction loans, and are working diligently to reduce prices on their products for the summer selling season. As a result, with reduced pricing coming now and soon to more developments, the amount that can be negotiated will likely only be for upgrades, interior finishes and closing costs rather than for pricing changes. This doesn't mean you should not ask for price adjustments, just be prepared if the only thing the developer can offer is non-cash incentives.
As always, for those who feel more comfortable doing this with a Realtor, then bring a Realtor with you to the FIRST visit to the complex to register the Realtor with the sales office. Otherwise, if you feel comfortable, you may certainly negotiate with the developer and call to their attention the fact that any savings that are realized since you do not have an agent could be passed along to you. If you need only a Realtor to be present to help facilitate the transaction, then consider using a licensed agent who will work with you to facilitate the transaction only. Check my blog here at Trulia for more information on facilitations.
Good luck in your home purchase!!
Grace Morioka, SRES, e-Pro
CID/HOA Specialist, Forward Planning Consultant for New Home Developments
Area Pro Realty
San Jose, CA