I should add that he has specified for it to be piston filled via a bottle of ink rather than normal cartridges
http://www.johnlewis.com/montblanc-meisterst-ck-legrand-piston-fountain-pen-black/p783525
Something like that but cheaper?
Or is it better to buy a 'converter' and a normal fountain pen?
http://www.pelikanpens.co.uk/acatalog/Pelikan-Souveran-M800-Fountain-Pen-Black.html
Still too pricey?