Electronics are expensive, as are appliances. You might want to check out Court's website
http://www.courts.com.bz/Default.aspx to get ideas of prices in Belize City.
I was told not to get the furniture from the little (Mennonite?)shop in town, as the wood is from the mainland and may carry insects that will come out of the wood and get in your house. I don't know if that is true, just what I heard, but I didn't want to take that chance.
Also, Lovey ordered my Supreme mattress. It is pretty comfortable, especially after hearing the horror stores of nice mattresses not being available. Thanks, Judy!
You can also check out a little of what is available at Sam's Club in Chetumal at
http://www.sams.com.mx/ The catch is you have to know Spanish and can convert pesos to dollars.