In Path of Exile, price fixing scam is by now pretty well known, it works as following. The scammer will place a high value item up for a lower price than what it’s actually worth on PoE.trade, they then wait for people to post the same item for a lower price than theirs and buys it immidietly. The scammer never sell their price fixed poe items if you ask to buy it.
Now there are scenarios where some people think that price fixing is happening but is actually not. A scenario where this is common is when someone find a good rare item and post it as the cheapest one compared to similar items on PoE.trade.
Cheap, good rare items are usually sold within 1-5 minutes especially at the start of a new league. So after the seller has sold his item he will continue to get mass amounts of whispers wanting to buy it, to all he never responds. Some of the people messaging this person who don’t get a response will think the item is price fixed.
Just remember that good, cheap items are sought after and most likely 10-100 people other than you will message the seller for it if it was posted recently. A simple way to confirm if it was price fixed or not is to check the item again in 15-30 minutes, if it’s gone then it’s confirmed that it was sold before you messaged and not price fixed. Where real price fixing often occurs is rare semi-expensive/expensive items.
The way to counter getting scammed by this price fixing method is to simply ask other people what your unique is worth before listing it. You can ask in global (as mentioned by u/Moldydwarf, please take this into consideration if asking in global or trade channels: Please don’t do this on global 820, or trade 820 for that matter. They are not a price check channels.
It’s also very important to always scroll down when checking prices of unique item, to the more expensive ones. Because then you might realize that the unique is price dependant on a single roll of one of its stats, or that the first few listings are very cheap compared to the 100 others. Which is a good indicator that the first few listings are price fixed.
So scroll down, research your item a bit, ask around and you should have a good better grasp of what it’s worth. In fact, buy poe orbs on U4GM is always an excellent choice, because it is safe for you.