The wergild (also weregild), or "blood money" was the price for killing another person which varied with the person's social standing. The weregild for a freeman was roughly two hundred shillings; for a churl (slave, also known as a "thrall") the fee was nominal, not much more than the value of the slave.
Ealdorman is the old title for a noblemen which later evolved into "alderman," or in some cases "Earl." They were always considered members of the nobility. As late as the ninth century in Mercia, an early kingdom of Great Britain, a nobleman commanded a wergild of twelve hundred shillings. Interestingly, the king himself was valued at thirty thousand shillings.
To calculate a more accurate value: twelve shillings equaled one pound of sterling silver, hence the term "pounds sterling."