OK possibly a daft question - is the examiner in-house? If so, then I would have thought the rate would just be an instructor rate like what the paying punter (i.e. me!) has to to pay for an LPC. Why would/should an employer charge more.
If the examiner is external from, say, another operator, then surely their rates would/should be quoted in advance? So whoever your examiner is for an LPC, ring 'em up and ask 'em!
Cheers
Whirls