They will charge top money for one tyre and give you the other one for "Free"...
If you want the new tyres balanced, they will charge you extra.... x2
and dont forget they will charge you for new valves ... x2
Oh and a small fee for disposing of the old tyres.. x2
Not quite the bargain you thought it was..!
Just go for budget tyres at your local garage, doing 3000 miles a year.. you should easily get 3 years from front tyres.
Better still get a quote from both suppliers, and play one against the other to get the best price.