However, if you are looking for decent rads, such as Myson or Stelrad, try getting a price for a 'radiator heatpack' from Plumb Center. You should find it cheaper than buying all individually. Make sure the sizes and styles (K1 P+ K2) are matched to your rooms.
I think he wanted a price for a professional to supply and fit them.
Most heatpacks I see tend to use the cheapest rads to keep the price down to about £750!
Tony