John, I think he gotcha good...
I'm surprised at the Canuck pricing. Down here in the 'states MB batteries are priced competitively. I just went through this last week - the original battery in my '98 finally gave up the ghost. Dealer price was $109, which is competitive with a DieHard or Interstate group 49. McParts stores will have a group 49 for ~$60 or so, but I've averaged one year of life, followed by a sudden (and inconvenient) death on those batteries, so no more for me.
BTW, I'm definately a battery snob - I have Optima orange tops in both my MBs. The Optima is a great choice for the 210, since the battery is under the rear seat.