Garmin has announced 47% discount on the Garmin GPS Map 62S + OS 1:50K GB Mapping all of those who are in Mountain Rescue or are associated to Mountain Rescue plus on the Montana 600unit.
Whilst this is a good price, it includes Ordnance Survey mapping that English, Welsh and Scottish teams can get free of charge, so if you are procuring, or thinking of, one of these units from Garmin I recommend negotiating further discounts.
For details of free mapping please see the thread My new Garmin 62 - but how do I use it in Satnavs. Started by Phil
Plus, for MR field use the 62 series is superior to the Montana range.