Dunno where you got those figures. The Information Please Almanac lists:

War of 1812 (1812–1815)
Total servicemembers         286,730
Battle deaths         2,260
Nonmortal woundings         4,505
Wikipedia states that about 15,000 died from causes directly related to the War.

British casualties (Wikipedia):

British losses in the war were about 1,600 killed in action and 3,679 wounded; 3,321 British died from disease.

There doesn't seem to be any casualty figures for Canadian militiamen or Indians fighting for either side.

There's also this:

at least 3,000 American slaves escaped to the British because of their offer of freedom, the same as they had made in the American Revolution. Many other slaves simply escaped in the chaos of war and achieved their freedom on their own. The British settled some of the newly freed slaves in Nova Scotia. Four hundred freedmen were settled in New Brunswick. The Americans protested that Britain's failure to return the slaves violated the Treaty of Ghent. After arbitration by the Tsar of Russia the British paid $1,204,960 in damages to Washington, which reimbursed the slaveowners.

Depending upon the index you use, multiply the amount Britain paid by USD 14.60 (for purchasing power) or USD 182.00 (for unskilled labor) or USD 15,900.00 for Consumer Price Index for the cost in 2010 dollars. If you want it in pounds do it yourself.