How many songs do you need?

I have often wondered exactly how many songs I need to be a "folk" singer.

My main interest has always been songs collected in my home county Hampshire UK – and the collected Dr. George Gardiner collect some 1200 songs there from 1905 to 09.
The singer who gave him the most songs over that time was Mr. George Blake of Emery Down, later of St. Denys, Southampton – he gave Gardiner 48 songs. Now this was probably not Georges complete repertoire – I am sure there some songs Gardiner just didn't want.
There were examples of singers who had huge stores of songs – for instance, Henry Burstow 1826 to 1916 of Horsham Sussex – who was said to have 420 songs in his repertoire – I am sure that was unusual in those days – but what about today??
I think I could sing at least 150 songs fro memory, and a lot lot more with the words in front of me – thereby I know the tunes – but how many do you really need??

Tim Radford