Hm.. a local locksmith said he could dup my W124 key for $30. Ouch..

I only have one of them (used car) do I *need* to order it from MBZ or can I get it done at the local locksmith... or is the locksmith just high?
If I can order it for around $20 from MBZ I'd rather have the real factory key (aftermarket blacks are often of inferior quality and I've already had one car with a key that busted off in the ign.. oh.. how that stank).
I'll be watching this thread!