rear drivers side light for CLK 200 (2006)

[Margaret]

I need a rear drivers side light for my 2006 CLK 200 (registered february). My garage wants to charge 189 euro for the light plus labour 85 euro per hour plus VAT = over 300 euro. What websites does anyone recommend for getting parts like this ? - I have already seen one where I can get it for 130 but was wondering if this could be beaten ?