Scams

Coins

Don't buy coins from other players
Heim coins sell to merchants for 5,000H each
Lucky Coins sell to merchants for 50,000H each
People often try to sell these for 10x to 20x the price

Stones

5,000H to craft a Maxi Stone/5 fragments @ 1,000H each
20,000H to craft an Over Stone/6 fragments @ 3,333H each
80,000H to craft a Strength Stone/8 fragments @ 10,000 each
320,000H to craft a Mega Stone/10 fragments @ 32,000 each
3,000H max to craft a Protection Crystal/5 fragments @ 600h each
5,000H max to craft a Shining Crystal/6 fragments @ 833H each
198,000H to craft a Noblesse Crystal/13 fragments @ 15,231H each
5,000,000H to craft a Strength Crystal/10 fragments @ 500,000H each

Strength Stones are high demand items

Ethers

Ethers are common drops

Imp

imp = Imperioum, used in Elite crafting
Current market price seems to be around 7,000,000H as of 8/29/2010

Private Shop

What makes Private shops different from trading is that they are more secure and will give you no chance of being scammed. If someone offers way more money for an item than it's original value they are most likely wanting to scam. To avoid this you set the price of the item in a private shop instead of trading. When trading some players may bug the system to scam you at the last second.