Should I get a iphone 4s from ebay?

So on the apple website its around £450 however, most of them on ebay are £250. Should I get it from ebay? Or will it be really rubbish? How can I trust it will be good?

Ebay is not a good site for purchasing mobile phones and there are many fake iPhones too. So you better be careful.

Yes but you must pay by PayPal to be protected PayPal is a site that will protect your money if the seller is a scammer and you don't receive your item or is faulty
eBay always has cheaper prices I've used it for years it's a great site and is safe if you pay by PayPal and apple store has the most expensive prices its cheaper to not buy via the apple store

I wouldn't if the phone is reported stolen at a later date then you will be left with a locked phone, also often they will be locked to american networks

No not from ebay, there's to many fake websites. Try CEX