Voluntary PRSI contributions

The OP referred to signing on for 8 years. My response was in that context.
 
Interesting thread. So is the below scenario correct - ie person could get full Contributory State Pension with.

10 years working paid contributions - 520
10 years credited contributions - 520 (this being max no. of credited contributions alllowed - ignoring carer scenario)
20 years of voluntary paid contributions (at €500 per year) - 1040
 

In theory this might be correct. But I doubt that anyone will ever come up with such a result on pension day.