Depends on how much £15 and a bit of time is worth. Exactly the same software (well, advert at least) can be found on ebay. All the software is essentially PD, and the parallel cable details can be found in the Aminet hard hacks section.
There again, for some people the prebuilt cable and, say 3 day wait for delivery, might be worth £15.
Much faster results can be obtained using Samba (public domain) and a network cable.