Following on from the 'secondhand CDs' thread, how much does the copyright owner expect when you include their song whilst recording a CD?

If I record ten songs on my PC Studio program and burn it to CD what percentage do I send to the songwriter?

For example :-

CD sells for £10
Cost of cover printing, writable disc and case is £5
Ten songs @ 50p each.
10% to writer is 5p
50% to writer is 25p
Doesn't seem much!