I've booked three tickets to take the GC to Aladdin at The Prince Edward Theatre, London just after Christmas, total cost £178, no concessions.
They were the cheapest seats with a decent view and we are in the gods, upper circle.
For musicals and the like you don't need to be in the royal circle, my first choice, but I do like central seats and not out on the periphery. I took GD to see 'Matilda' and again we were in the cheap seats, about £60 each, but I'd chosen carefully and it was great.
I always go on the Theatre Monkey website which gives information on seats in any London theatre e.g. the front row in an expensive royal circle might not be a good idea as there is a safety rail obscuring the view and you have to lean forward.
Seats