There have been reports on some model years of vibration but I don't know that the 2005 model was included. Historically, one of the main culprits that caused vibration was having the idle speed set to low so that would be the first thing I would investigate.
If I was in the market for a vehicle I would focus on the previous maintenance records to get an idea of what kind of care and feeding the vehicle has received. If I had questions about the overall condition I would have it looked over by a mechanic that I trusted.
My '07 with 93k on it does this, a little. I suspect it's time for spark plugs and maybe a valve adjustment. Also, check the oil. You might check to see if the inside of the throttle body is dirty, and whether the air filter is dirty. I doubt it's a serious issue.