I tried to purchase the Nexus 4 via Chrome on my iPhone, but there was no Buy Now button on mobile. I even clicked the setting that said "View Desktop Version", which reloaded the exact same page. No difference at all and no Buy Now button.
I then tried Safari on my iPhone. Again, no Buy Now button. I had to use a desktop browser to even see the Buy Now button, then I had the exact same experience. I had the phone in my cart and then it magically disappeared when I tried to check out.
All in all, this was an awful shopping experience. The phone was for my wife, but not having any sort timeline for when they will again be available, I told her to just go to Verizon and buy the best phone they have in stock. Google will lose a sale in this...which is too bad. It looks like a cool phone, but they can't manage a supply chain or a webstore apparently. As a Google shareholder, that scares me a little bit.