You say affordable down near gatwick for £5k - £5.5k a month...but tie in the fact that there is no pension so you have to save for your future yourself. There's a chunk coming out every month before you've even started. £6k sounds like it would be ok, but any less than £5k isn't worth it, not for a non-permanent contract. If they had a pension scheme and a permanent contract, £5k a month might be ok (ish).