To those without record deals, who press up their own CDs:

1.        The most expensive part of CD duplication is the packaging. If you get your CDs duplicated at a pressing plant, you will save a significant amount of money if you just order CDs on a spindle: ie the CDs alone, without any wallets or jewel cases. Buy your own wallets or jewel cases (or whatever) separately, and, if you have time, print them yourself at home with your printer. I'm about to get 1000 CDs duplicated and it will cost me £350. I'm going to use paper sleeves (which cost 3p each). Jewel cases aren't bio-degradable anyway; not very green. I'm printing onto them at work, using the work printer. This means I can sell CDs at anything from 50p upwards and make a profit. A CD for £5 is a 500% profit.
2.        If you're registered self-employed, then the costs of CD production are a tax-deductible expense. Any CDs that you give away are promotional; also a tax-deductible expense.