ranges between £400 to over a grand in my experience depending on what kind of skill sets.

Remember that scaling this kind of business is hard because you are selling peoples time - so for each salary you pay you can only sell it one time over. Compare and contrast with being a product company - I might spend a few weeks working on a product and then those few weeks of my salary can be sold over and over again.

The scaling of so many employees also brings massive overheads.

So yes - the day rates seem high but the margins can be pretty rubbish.