Spa is one for the enthusiast, mainly because it can be very unpredictable on the weather side and that you need to do a fair bit of walking to see all the good bits. It is one hell of an amazing sight seeing the cars go through Eau Rouge, Blanchimont and Pouhon mind 8)
Monza is not as exciting to watch but the atmosphere is something you have to experience at least once. The Tifosi make the place become something that has a life of it’s own!
Did both (and Hungary, Germany, British and Monaco!!) over two years camping in an old Volvo 240 Estate back in my 20’s so can’t help on the deals front. Done Le Mans with Grandstand, Motor Racing International and Select Motorsport so might be worth looking into their deals.