I disagree. Tourists travel and tourists are used to paying a certain amount.
When tourists go to London, they get a sticker shock while paying 4.5GBP because comparatively its a fairly hefty amount. Then tourists come to HK and take the Star Ferry, they find the price ridiculously cheap and they ride it with a smile.
IMO, MTRcorp has chosen the price of a tourist-targeted product to be higher than locally targeted product; I think its fairly priced.
Take a look at a different example:
Star Ferry (targeted at locals) : around $2.xx
Star Ferry The round the harbour tour (for tourists) : $85 - $215
Most will think its perfectly normal to pay $10-$30USD for a ride on a boat for a couple of hours (while its called a tour) and tourists will happily pay it. I personally think its ridiculous to pay 100 to 200 times the price of a single crossing
Look at prices being charged at hotel minibars, hotel bars and tourist geared establishments. They are set in line with expectations of what the consumer (the tourist) will be happy to pay for as opposed to the 7-11/local bar across the street. Those prices are arrived at (and maximised) based on what other big cities are able to get away with....it's like saying why not charge them higher for a glass of beer as long as it's cheaper than NYC or London.