We're not actually going to take the claims of an E-bay seller at face value are we?
If it was custom designed and goes for close to its starting price it would appear to me to be a bargain (compared to the cost of design and production of such a mould) - and you could easily recover the investment in a year (so long at you turn out boats faster than Codprawns prosport!).
The speed claims are a little OTT, perhaps km/hr rather than mph?