The common, "look its being shilled" gotchas have been well known by shillers for 10+ years.
The lazy ones might get exposed by %bids with one seller, # of bid retractions, low feedback users...
Professional/experienced shillers havent done it with those types of "mistakes" for years and years. You can never know for sure, but the key to catching shilling in this era, is to look for bidders acting against their own interest. That cannot be hidden no matter how savvy the shillers are.
That includes:
1.) Raising the price significantly, long before the auction ends
2.) An extremely unusual amount of bidding. (Very few people bid 14 times on one auction)
3.) Bidding up an auction past the BIN price of other auctions for the same product.
The goals of shillers is one of two things:'
1.) Probing - (trying to get legit users to max their bids)
2.) Locking in Fake sales - (where they sell within their group, or too themselves, in order to create a fake 'floor' for something they will try and sell legitimately later/)
Wow, this is a "shilling primer". Naive probably, but I never expected it to be this involved. I generally only buy collections, lots or BINs here on the Boards.