If by being fully prepared you mean: Having a downpayment and funds for closing cost, and being pre approved for a mortgage, the answer is, you should be fully prepared prior to contacting an agent to view properties.
If the property you are thinking about has been on the market for 151days and is still an active listing there could be some issues with getting the short sale approved, or perhaps the property is in very poor condition. If you are tarcking the property on a consumer based website the info you are getting may not be current. The home could l be showing as an active listing in error.
Short sales are moving just as fast as regular sales theses days. It is common to see multiple offers on them as well.
You should be fully prepared to buy prior to looking at properties. This way, when you find something you like, you can make a move on it without delay.
Best of Success to You,
Kawain Payne, Realtor