General trading guidelines

Rares, the price fluctuates. As such, they won't be covered here.

The price an item high alchs for is the same as it's price checker.
The high alch value (H) is 25% HIGHER than the GE sell price (S).
The buy price (B) in GE is 25% HIGHER than the high alch price.


Therefore, to maximize profits, you would want to sell anywhere between H and B, so you always profit, and buy anywhere between S and H (so you can alch it later or resell).

However, you're (probably) not going to be able to buy under H, so any less than B is a good price.