Bartering, Money & Haggling

Bartering and the exchange of money for goods/services are regular occurrences. Both are routinely carried out in most countries round the world in some form or another. Bartering is the most common out of the two, considering the majority of individuals would not be of high enough rank or title to have monetary funds available most of the year. High ranking members of a society would have sufficient access to money or other valuables to pay for goods and services the vast majority could only dream off. Most societies have a Mint to make coinage, with some having more than one. This is usually due to the size of the relevant society, and the problem of having to transfer large amounts of metal coins to different regions, not to say of the problems of highwaymen & bandits. Most nations will accept coinage of others, sometimes with slightly different amounts between the usual 1:1 ratio, due to were it comes from. his doesn't bother most individuals as it's not that common.
Most services and/or goods are done by a bartering system, usually at lower or middle class levels, including adventurers at times. This can range from carrying out work on a farm for an overnight bed, exchanging a certain amount of livestock or meat for new tools,  or even killing a big bad monster attacking a village to become the local mayor for the term of a year. Most bartering involves trading one set of goods (or work maintaining them), to specific tasks, being exchanged for an equal value of other goods or services, according to who is involved. An example is a blacksmith making, maintaining, and/or repairing mining equipment, in exchange for a certain amount of metal ores and/or gem lodes the miners have dug up. Sometimes this type of system is used by the upper classes to get goods for day to day living while giving out a bit of coin into the local economy, and the protection the upper class provides militarily. These can be stored and used even for tax purposes when the tax collectors come knocking.
As for haggling this happens irregularly in the Far East and Europe, and seems to be more common in the Middle East. It appears more as a cultural trait than anything. A price or equivalent is set by the trader, craftsman, noble or whoever, and then the other party is expected to politely argue the price down to an amount both are happy with. When set the deal is done. This amount changes over time and between different parties, and the same buyer & seller might agree on a different set amount at a future date.