Steven is correct that the value won't be changing much but the prices there will continue to go up. So, from a financial point of view, you would get a good return on your downpayment investment especially if you buy now.
The rationale for the discount today is that the builders are selling a life-style. At the beginning of construction, your new home is in the middle of a construction zone, not that attractive. So, the builder gives you a discount. As the project is completed, the community is more livable and attractive to buyers. This drives up demand and prices.
I've just sold a unit in the complex in the last few weeks and prices are already up $10K. If you had put down 10% to purchase, that would have already yielded you a 20% return on your downpayment. If you have any other questions about how builders work and how to get a deal, please let me know.