Interestedparty
Before any money would be spent on updated blind flying euipment the airline would have to look at the number of times flights are cancelled or diverted, this I believe has already been done in the past and although Bristol may suffer a disproportionate number of cancellations the rest of network operates generally with no problems to Cat II standards.
It doesn't help of course flying into an airport 600' up in a part of the country with a poor weather record at certain times of the year.
Yes the Emb 145 is cheap compared to similar aircraft as will be the Emb 170/190, why do you think airlines have been buying the 145 and are starting to queue up for the 170/190 economics, it can be the difference between surviving and making money or going the way of a great many other airlines.