Whilst our cars came with Continentals, we've not replaced them with more Contis - on the grounds of cost as much as anything else, as they always seem notably more expensive that other major brands. That said £90 per corner is pretty good!!
I have the same fitment on the front of my C-Class, and went for Pirelli P-Zero Ross Assymetrico (catchy name eh?) - in a Z rating. They do a Mercedes specific version with a Y rating that worked out less than £500 front and rear. The Zs were a little more expensive, and are not MB-specific.
So far so good, pleased with them - too early to tell what wear will be like, and I drive like a daisy so have no idea about the effect (if any) on handling!!