Back when I got mine I used Dabs, very good about a replacement when the internal power circuitry went wrong after a few weeks too - printed a label and they sent a courier to my work to collect.
I've heard that G25's are in short supply though, maybe Dell didn't have any left and weren't aware there's a shortage and gave a standard ETA. What they said on the iRacing forums is that Logitech said they are dependant on stock from China that hasn't shipped because of the Olympics.
I guess anyone with a live stock indicator showing it available (like Amazon and Dabs) you'd be alright to order from.