For what it's worth, my experience at the shows is similar to your experiences. It's hard to get any discount. I bought a Warco WM18 mill with no discount but was offered some tooling to go with it at a small discount. I later bought a gear head lathe again with no discount and no extra tooling offered. Even attending the advertised open days at their home site resulted in no discount.
I think the days of discounts – even small ones are over because of the financial climate we are in. I still go to the shows for advice which I think is sometimes worth quite a lot so I go prepared with my questions and anything I need demonstrating which I have to say Warco are very good at and will spend as much time with you as necessary even if you're not buying anything.
I go to all the major shows and am going to Harrogate as usual as I think it is one of the best shows now. A lot of the shows are suffering with reducing attendance by the trade due to costs. If they don't offer a reason to buy at the shows, then people will just buy via the Internet (me included) which will make the situation worse. Of course, the shows are not just about tools and equipment. I spend more time going round the model displays and the clubs picking up as much information and hints and tips as I can. It's a really good opportunity to meet up with those that have got the T shirt so to speak and help you avoid some of the mistakes they have made and learnt from.
A