Your questions are typical of the many that people contemplating moving to a new area have.
As far as "gated community", that's more common in the price range you're interested in that it would be in the homes in the median price range (around 250-275K) when you consider the entire area. Most of those are in the more recent construction areas (since mid 90s) and I'm sure that it was part of the marketing considerations of the builders to add a sense of exclusivity to their new subdivision.
As far a pricing goes, you'll see that a little more frequently in a hot market like ours, just as you will in a depressed market. It's a little more common on the extreme ends of the bell curves. When sellers perceive a hot market (we are truly in a seller's market) they often insist on a price that is too high for the actual market and Realtors will list it at that price, rather than the one they think is the true market price, to secure the listing with the understanding that the seller will reduce the price if it hasn't sold within a short specified time. Sellers often have an attitude best reflected in "you can always come down, but you can't go up" and perhaps, they think they'll get lucky. Bottom line, homes priced properly for the market are going in less than two weeks around Austin and the only ones that don't are over priced. Either due to the poor condition of the home, some undesirable quality of it, or just flat out over priced.
In any event, your agent should be able to look at the market and a home and give you a reasonable expectation as to correct price. Trulia and Zillow claim a lot about that, but they are simply unable to give accurate estimates of pricing in Texas. Texas is a closed record state and the sale of homes is not in the public record so Zillow, Trulia and others of their ilk are just GUESSING! Not the smartest way to look into purchasing a home.
If you would like to discuss our market and gain a better understanding of it and Austin in general, please contact me by phone or E-mail and we can begin an honest discussion of Austin and the surrounding area that will satisfy your curiosity.
Realtor, GRI, ABR, CRS, e-Pro, CLHMS
To add to something Roland said - You can get access to actual sold pricing data here in austin. All you need is an account with Redfin.com. As a RedFin user, you will have access to ACTRIS data, and thus actual sales prices. This information can be very interesting and useful.
I live in Ontario, Canada (very close to Toronto) and its considered very safe where I live, that's why I'm asking this strange question.