£55!!! That must be south coast prices.
The first three quotes I've had to supply and put up a DAB aerial in London were no less than £160!!!
I have a 4.5m extending ladder, but like you say I don't have the equipment to test for the best signal etc.
I was thinking of installing a better TV aerial as mine is tiny in comparison to my neighbours and I can't get much in the way of freeview either!!! Lucky I have Sky in the living rooms, but I wanted freeview for the other rooms.
All my neighbours have much better Freeview reception even when my freeview unit is plugged in.