I've had some real bum deals in the past.  I am getting better at spotting scams, but anyone can fall for them.  Here are some of the best, and how I should have avoided them.

1.  "SEALED SETS".  I paid $2000 for an enormous pile of lego that came with several dozen "sealed" sets.  When I got the item, almost all of these "sealed" sets were indeed sealed: with stickytape, and had random piles of blocks stuffed inside.  Not only that, the pieces in the overall collection were not even from the sets represented by the boxes.  Needless to say when I emailed him he did not reply.   SOLUTION:  check if the boxes are factory sealed, and also check the feedback; the guy had a lot of negative comments.

2.  STAR WARS ARMY.  One user had gathered several pictures of massive scenes of Star Wars lego figures and was selling this as their own property.  He'd also piled up a few big boxes and claimed that the figures were accompanied by over 100kg lego.  I'd put a nice juicy bid on it when another ebayer alerted me to the scam.  Ebay delisted the item and the user.  SOLUTION:  I blew it.  Thank God eBay eliminated this guy before I had paid.

3.  SECOND CHANCE OFFER.  Some wiseguy sent me a "second chance offer" email for a truckload of lego I had bid on (literally, a truckload...).  I'd bailed out of the bidding at the "redraw on house mortgage" level of cost, so I was a bit off the pace.  A few days later this email pops up offering the lot to me at my maximum bid.  SOLUTION:  the sender of the email had a different user ID to the original seller.  I saw that, and the whole feel of the email was dodgey.  If in doubt, don't.

4.  OUTRAGEOUS POSTAGE COST.  I bought some lego from the UK and the seller told me that they could ship it only in 2kg lots and I had to pay for 6 lots of postage.  The seller's feedback was OK, so I assumed they were on the level.  Needless to say it was a load of bollocks, and I never received the lego and the seller disappeared.  SOLUTION:  I'd have been better off with an unpaid item strike; some people have no scruples.

5.  POSTAL INSURANCE.  Many sellers attempt to get around paying eBay fees by selling the items at low cost but having a high postage cost.  This is easy to spot, as the postage will be stated in the item description; if no postage is stated, be careful.  One nice variant on this was the "optional" postal insurance.  The seller said insurance was optional in the ad but when I bought the item the insurance became mandatory.  The guy charged $15 insurance for a $0.99 item.  This seller then kindly offered to give me negative feedback if I refused to pay the "optional" insurance.  SOLUTION:  Always ALWAYS look at the seller's feedback!!  This fellow had dozens and dozens of negative remarks due to the same scam.

THIS WILL BE UPDATED AS FURTHER DISASTERS OCCUR.