Just because you get paid by the NHS doesn't mean that you'll accept anything when doing contract work. These people are giving up part of their annual leave and for that I certainly would want to be well rewarded, not the equivilent of a couple of hours O/T. Also the take up on the offer of work was very low as most people like me wouldn't touch it with a barge poll, so I imaging they get paid a premium.
There's no NHS conspiracy here you obviously put in a quote and just like anywhere in the world including in the NHS another company put in a lower bid which was considered better and won the contract.
Ps. I've checked out your website and I find it very ironic that your moaning about biomeds taking your contracts overseas when your trying to take theirs in the UK!
