I've sold pretty much all of it with only about £500 with now. I've met loads of people who do it as an investment/ business ( I rarely posted sets and made them collect so they'd usually end up buying more ) and there's still a market for it but there's loads more doing it now than when I started doing it so it's harder to make it worthwhile.
Still, all the sets, and there are many in our house, have been paid for through the ones I sold.