In response to janeyTA, travel agents, for example Dawson & Sanderson do add there own commission on top. It was like last time we tried to book a holiday with them through Jet2holidays, and they added almost £400 on top. I know this because I had done my research, and the Jet2holidays website stated the original price, without the +£400 they had quoted. After confronting them, and showing them the live price on my phone, they quickly realised, and after this said on this special circumstance, they would match the price that Jet2holidays had quoted online - of course, after phoning LS up. It later turned out that they have their own variant of the website, a one adapted for travel agents, with these extortionate additions on top.
D & S often package their own, but unless you were spending thousands they're unlikely to put £400 on top. Jet2holidays reckon they're agent friendly when in reality they're not because they discount online, and the price Jet2holidays put on agents viewdata is a lot more expensive. The agent isn't adding the extra, the tour operator is. The agent price matching your online price has most likely taken a hit on that booking unless Jet2holidays agreed to pay the agent the difference. They can't stay in business if they take hits on a regular basis. If you wanted the online price you could have done the right thing, and booked online. That way the agent wouldn't have lost money or at best, made nothing.