Good find!
They're really good value mate. Delivering a big chunk of cast iron like that for £20 was a no brainer purchase for me.
The friend who has one wiped it with oil and put it in the oven for a second seasoning, and he's never had any sticking. I've not bothered, I've given it a good wash in hot water and a very scant rub with an oiled cloth and I'm convinced it'll be just fine.
Should you buy one, I have a PDF of excellent recipes that I can email to you. To start you off, Blooming Onion Bread. I really need to get mine cooking this season.