Hm, well there's issues such as:
Firstly MAKING the tracks and compiling a CD.
Next, getting a decent enough mastering service.
Also you'll need to setup your own label as a registered company.
Once done, you'll need to press the cds and pay for jewel cases, artwork etc.
Then you'll need to pay for distribution.
You're probably looking around £0-2000 for step one, depending on what synths you need to buy
Not sure on mastering...
I'm not sure on how much it is to register a company either (off the top of my head)
The more CDs you press, the price should go down per CD - but usually for 1,000 cds you'll be looking at about £400-500
Distribution - these are the guys who will deliver the CDs to the shops - they'll pay you once they run out of stock - so it could be a few months before you see profit.
I'd say in all, you're looking around £1,000 to release a CD on your own record label.