I'm about to hit 4 weeks on this game and I still have NO idea how to price and sell something. I have 1 ex and like 24 chaos. I just learned the chaos recipe. Teach me master!
Well, the key to selling things in PoE is to set up a shop in the forums to get the indexers to pull in your items. Most players utilize poe.trade to find gear. Once the indexers have your items you will start to get messages from players asking to trade. If I have a unique, gem, or map for trade I go to poe.trade, look up the lowest price and charge a little bit more than that.
Rares are a bit more tricky to price. It's really up to you. I recently had a 2000 evasion chest with triple 40 resists and an open slot to craft life for sale. I had people message me every day about it. I asked for 7-8 exalts for it. Some people laughed and said I over priced it. Other people simply said it was out of their range. I got 1-2 ex offers and 30 chaos offers. But yesterday I sold it for right around 7-8 exalts. So what was the chest really worth? To some people it was worth 30 chaos. To me it was worth at least 7 exalts. It's up to you how you price your rares, but you might have to drop the value to sell.
Other tips:
1. Use a 6-socket item in your weapon swap to level gems. When you level them to 20 sell them with a GCP to a vendor to receive the 20% version of that gem. You can then sell those for 20 chaos or more.
2. Or, instead, then level those 20% gems to 20 and use a vaal orb on them. They can roll up to level 21 in this case.
3. Or, instead just level aura gems to 20 and vaal them, trying to get level 21. Quality on aura gems only increases the area effect which most people dont care about.
4. Watch The state of the exile and build of the week youtube videos. Sometimes these videos start buying trends that last for most of the league.
5. Watch trade chat. Once you learn pricing and conversions for currency you can find people who want to make a quick sell. They will be offering pretty good deals that you can capitalize on. Sometimes this is flipping, but I've found flipping to be fairly difficult since often you get stuck with an item instead of currency for a few days...
6. Use one of the chaos recipes. You can sell an item from each slot over ilevel 60 to the vendor in return for a chaos (2-handed weapon, chest, amulet, 2 rings, goves, boots, helm, belt). If these items are unidentified you get 2 chaos.
If you have any other questions feel free to ask. I'm not the best at this, but I make enough currency to get by.