If you do buy, demand that the builder give you the previous discounts plus more. Show them that you are willing and able to buy and factor in at least a 5% decline for next year. If you find a home already being built without a buyer/a buyer dropped out, you can demand even greater discounts as builders are eager to sell these homes and often offer huge discounts to do so. You are in the drivers seat my friend. Instead of stopping by every two weeks to see what the prices are, why not stop by today and set your own price. Most builders are very eager to sell homes by the end of the month due to business planning, tax and public reporting reasons etc.
EG: Factor in the previous discounts for the home, subtract an additional 5% and tell them you will buy it tomorrow. Instead of an additional 5%, maybe they work out some kind of financing where they pay your mortgage the first year, some of it the second etc, or perhaps upgrades instead. If you have to, threatening to just walk away can often work. For example, when you present your offer, tell them that if this deal doesn’t go through this week, you plan to just rent for the next two years and wont come back again. Tell them that you will be leaving town next Tuesday and that you need an answer this week. Lastly, make it clear that you are not interested in half ass couterproposals that they will surely try to present you. Do all of this in a tactful manner and I think you might have some luck!