[mmccomb]

Would bulk be a factor here?

As the size of the consumable increases so does it's shipping cost and difficulty. Which in turn might imply that fewer people would buy a TV online, than say a piece of clothing or a DVD. This is turn would force consumers to overpay for their TVs, not many high street shops can compete on price. This inflated price is in turn passed on to the 2nd hand buyer when the original purcahser experiences regret for the high price they paid.

Then again, I could be completely wrong.