2002 Honda Accord Keys

I lost my black master key. I have the grey valet key, which works fine but with 2 drivers we need another key.

Can I have the grey valet key copied at a hardware store? Or is there a chip in it which needs dealer programming?

Dealer quoted $80 for a new master key and $100 if I bring in my own blank!
The only use I see for the master key is to lock the trunk from the inside, which I can live without.