Price

"Everything has a price", so goes the old saying. However on Runescape (as in real life) eveything has several prices.

Store prices
When the store buys items, they will pay and charge most for the first item they by into their inventory, and less for succeding items, until a minimum price is hit at around 31 of any item - although a different forumla applies to "small" items in speciality stores, for example runes and arrows.

However prices vary from store to store, with general stores buying cheaper and selling more expensively than speciality stores

Meanwhile traders buy like stores, and sell at a flat rate.

Alching
The high alchemy price is generally the same as the speciality store buy price when ithas the default number of items in stock. The low alchemy price is generally the same as the general store buy price when ithas the default number of items in stock. Untradeabel items appear to alch for zero coins.

Street price
Street price for items varies wildly, depending on the characters relative need for coins and items, to gether with caniness in bargaining. Indications can often be found on the forums. Foolingpeiople over street price is a common type of scam.

Real world price
While the game rules forbid the sale of items for "real world considerations" trading for cash does occur and can be seen on the internet auction sites among other places.