The mic might be $85.00 Les, but when you add in the transmitter and receiver the cost goes to round about $300.00 (for a Shure ).
I have one of these which my ex gave me as a present, but I have never used it. I can't help thinking it looks ever so slightly naff ......(IMVHO)
What I would like is the system which I saw the Scottish female trio "Chantan" use, whereby the mics are hidden in the hair, the transmitters are round the back on the waistband, and it is all totally invisible. Way kewl.
Only drawback is you need to have a sufficient quantity of hair .........