Luminaries.org has an interesting list of prices of medieval items (compiled by Kenneth Hodges). It consisted of extracted references from books such as English Wayfaring Life in the XIVth Century, J. J. Jusserand, London in the Age of Chaucer, A. R. Myers, Standards of Living in the Later Middle Ages, Christopher Dyer, English Weapons & Warfare, 449-1660, A. V. B. Norman and Don Potting, and several more. It includes tools, food, livestock, books, education, buildings, clothing, armor, weapons, funerals, and travel; and includes wages for various professions from mercenaries to weavers to kitchen servants to barons! It makes for a fascinating read and a great resource for medieval fantasy games. (Thanks to Jay for the scoop!)
The image below is just the "WAGES" section -- click on it for the full thing!
