Erotic 
collectibles generally aren’t showcased in the living room — they’re something most people would only brag about to close friends. But if you know the market, they can be curiously lucrative.
Odds are that porn DVD you bought online will never appreciate — even 50 years from now. But the sex industry has a deep history in various forms of culture and at various stages of media. That has proved enticing to certain collectors.
You’d think that 
with today’s proliferation of readily accessible nude pictures, adult films, and sex toys, the world of erotica is disposable; there’s always something new just a click away, so why bother to save anything?
But the depiction of sex has been a part of human culture for thousands of years. While it’s easy to think that the pornography industry is an invention of the last three or four decades, erotic expression reaches as far back as the 8th century BC.
Chris Morris: Journalist 