XP Source

Once you start enchanting tools, you start realizing that you really do want XP! Building Requirements:
 * Name: XP Source
 * Tax Modifier: 55 (5,500 per object)
 * Size: 20*20
 * Protected by the server: No
 * Limit Per City: N/A

A reasonable source of mobs, most likely a spawner, or another trustworthy source of mobs. In a mob grinder that provides XP.

If the XP Source is bigger then the 400 tiles that are required, every additional 400 tiles equals another tax modifier. For example a 40 by 40 plot is 1,600 tiles and that means a tax modifier of 55 * 4.