But nothing to do with the OP's situation.If you take £50k off one customer now then, if you take more than £40k from all other customers within the next 12 months, you are required to register for VAT.
The OP said the value of the contract is £50k, not that the contractor is going to receive £50k. In fact the OP already stated that he'll be paying for some of the items personally. I'd be surprised if he banks a third of that.
No one needs a lesson in the (VAT) obvious, thanks.blah...blah...blah..