Hi all, I've been asked to perform some workaround magic at a big event of around 600-700 people, I've never done an event of this magnitude and I'm unsure on how much I should charge, they also said they would be willing to put me up in accommodation for 1 or 2 days, but I don't think I need this.
I was looking at charging around £220/hr,
but I'm a little worried I don't want to charge too much and risk losing the work, and don't want to charge to little and devalue the industry

Nothing you charge will devalue the industry, only your place in it.

Business can afford it. If you think you worth it do it.

I'm so happy to see the last two responses. Couldn't agree more. The price you charge is between you and the client and concerns no one else.

It's best to negotiate with the client in person or by phone. You can guage their reaction to your offer and adjust your price if they hesitate. I'm terrible at negotiation but this is what I've been told. I don't tend to make adjustments on the spot but it gives me an idea for the next negotiation.

Did you mean Corporate event? If so, pay attention to little details when you go there. A simple misspelling of the corporation's product or an executive's name (as part of some kind of prediction effect) can hurt your reputation with them. Please do not take this as a dig or being part of the grammar police. It is only a piece of advice that was passed to me years ago when I called a product "Styrofoam" which is actually trademarked by The Dow Chemical Company. Here is an example of a cup (which is not to be referred to as "a Styrofoam cup).
http://www.forte-eps-solutions.com/styro......bec.html

As far as pricing, I totally agree with (D) All of the Above.
Best wishes to you and enjoy the gig