I'd say that's the going rate for a garage/mechanic. That's similar to what I was quoted:
It was 1 hour for each front corner and 1 hour to do the back end at £50/60 an hour.
While they've got it all in bits fitting the springs, perhaps consider getting top mounts replaced (for the cost of parts only) at the same time?
See if they'll not throw in a tracking check?