I go to about 40 auctions a year and I see many people who just can't seem to pull the trigger[bid} and then they walk around and say "boy you bought that cheap'. They often follow me around asking "what would I take for it?" hoping I will sell it for only a little more than I bid.
One time I bought a good running Farmall M with a wide front for $700.00. Right away a man wanted to buy it from me and I asked him what was his offer and his generous reply was $50.00 more than I paid. I took it home.
When you go to an auction pick out the items that you would like to buy and set your price. Bid until it goes past your high bid and walk away. Unless it is something you really need do not bid very high. Auction fever can cause otherwise smart people to make crazy bids and way over pay for a common item. Watch the TV series Storage Wars and you will see what I mean.
The gates you saw sold for two dollars might have gone much higher if you had bid.