What’s missing in the rent vs buy calculations is what type of loan you are talking about. I don’t believe you ever told us. Is it an Interest only, Option-ARM, 30 yr fixed, etc? That is ultimately the most important factor here.
I truly understand the pressures to buy, but you need to take a hard look at the consequences in buying now versus waiting until prices come back closer to a realistic level. Even if you can afford the mortgage, being literally “locked” into your home due to being upside-down for many years (unless you can come up with a huge chunk of cash to get out) can be pretty scary.
Also, if you’ve been in there every 2-weeks, they probably know you and are trying to scare you into buying to help their 2006 numbers. I’d personally call their bluff and wait until spring when they are competing against hundreds or thousands more new sellers coming onto the market.