It tends to work better if you tell them what you want and ask them for a full price, then they give you a full price, and you realise you haven't got that much money to spend, and if you can't get all of the stuff you want, you might as well not order xD Then they'll start talking deals to make sure you order then and there.
I don't think there's a massive relationship; one is based in Scotland, the other in Milton Keynes. There IS some sort of relationship though; (oddly very petinently), I have previously called Airsoftworld (or as they were - airsoft scotland), and had stuff out of stock, and they've been able to sell me it at their price, but from ActionHobbies' warehouse and stock. That *was* about three years ago though, so things may have changed.
I've noticed that AirsoftWorld has, since then, majorly downplayed their Chinese stock levels...