Well nesting you sought feedback and have received plenty!!
A few last thoughts from myself. I do agree that I think your calculations may be overly optimistic unless you are plunking down a ton of cash on the deal. If that is the case I bet that renting for another year, sticking the cash in a CD and sitting tight could be fairly lucrative. Also if you want to post your calculations including the details of your loan, downpayment and sales price, mello roos, property tax and homeowners insurance estimates, there are lots of inquiring minds here that will proof your work.
I have accompanied several clients on trips to the builders the past few months. Personally I have seen that builders have very much tightened up on concessions and even negotiations compared to the late summer. I think Juice’s advice is well intentioned however I do not know if the builders would bite on that. Still though it never hurts to ask right?
One thing I detected in your post is that emotionally it seems that you and/or your wife have already made the choice by stating that you are ready to go in this weekend and make an offer. This means that even if there are numbers staring you in the face that imply waiting may be fiscally correct, emotionally it may be to much to overcome. It may also cause strife with you and your wife and that is never fun. I see this more then anything else in my line of work. If you can stick with logic then great, if not then try to do what Juice said and get the VERY best deal you can. I do heavily agree with Perry’s post.
DEFINITELY do not look at how well people did in 2002 or 2003 and think I HAVE to buy now. Moreover thank your lucky stars you did not buy in 2005!