Having had a squint on their website, for non members, it's £40 an hour each, plus £40 an hour for an instructor (which for non members is compulsory). So, 2 people for 2 hours is 4X40=£160 plus £40X2 for the instructor, a total of £240. So, really, it seems he offered you a discount!
Does seem a bit top heavy to me, but I guess the non member clientele will be mostly city banker types up from the smoke on the annual paid stalking trip who want to check zero on their rifles. Looking at the membership, it seems you would pay around the same for that for the year. Maybe that could be your best bet, Cawdor118 if you would use it occasionally.