Leicasonic 25mm worth the premium?

Hi all

For the Panasonic DMC-GX1, which cost me 5,200 RMB with the power zoom lens. In China the 20mm f/1.7 retails for 4,200 RMB and the 25mm f/1.4 is 5,800 RMB. I know it's a killer lens but is it worth paying more than I did for the GX1 with kit lens? I love the way the GX1 handles and I've get some nice images so far, but for street work I definitely need a fast lens, so one of these has to be bought to bring out the potential of this body.