Hi, I am a fairly experienced investor and just bought my first house via online auction 2 months ago. I wrongly assumed that it was just like any other auction, but it went well for me anyway. I did get an excellent price, and was able to get title insurance/clear title to the property, so I would disagree with the earlier comment that there are no good deals.
However, please read the documents carefully. I did not realize at the time that many of the properties that are being auctioned are tax liens, etc. This means that in my state, Indiana, you would have to wait for a year, then would be responsible for notifying every lienholder that shows up on the title search, then would need to petition a judge to give you title, then submit a petition to the judge for a possession order, then deliver that to the sheriff, then wait for the sheriff to remove the occupant, then still not have clear title for up to 40 years (if there is a foreclosure involved) unless you spend another $1500 for a quiet title proceeding. So, if this is what you are buying, then you may be looking at tying up your money for 1-2 years and spending thousands in attorney fees to get clear title, or worse, not being able to get clear title if one of the lienholders challenges your ownership.
Luckily for me, the house that I purchased was not one of those. I purchased a house for $26,000 that is worth $60,000 and just rented it for $725 per month. No one tried to get me to up my price after the auction closed and it all went smoothly.