Have you tried local classifieds to see if there are any used kitchen cabinets. It's not the ideal, because of course you would want something that fits your style and is designed with the space you have, but sometimes people luck out. I recommend checking your local paper or, if you have any, website classifieds like craiglist.com. Keep an open mind, but don't be too eager to buy the first thing you see or you'll end up paying more than retail.
Don't forget to be very careful about buying through classifieds. Never meet anyone at night or in an area that is not considered public (i.e. farm in the middle of nowhere) and make sure that people know where you are going, who you are going to meet, and when you will be back. Never send money over the internet through a private seller and don't give out any personal information that can be used against you at a later date.