The price offered to you by the builder is quite attractive when compared to the “current market price”. And that’s expected, because builders are under pressure to generate revenues, so they have to offer low prices in order to sell houses.
The problem is: just as your current deal is better than the John Doe who bought last year, another guy who buy this time next year will get a much better deal than what you’re getting. In term of prices, we are nowhere near the bottom.
IMHO, the chances that prices will go down significantly more is 99% (the 1% is for the scenario in which another “credit bubble” appears to pump money into real estate).