Ahead of Google's Android event on the 29th there's additional confirmation of a storage upgrade for the Nexus 7, as 32GB units have now been spotted on shelves at US retailers. Seemingly dead-set on matching the LG E960 "Mako" Nexus G for the title of worst-kept secret, we've received this photo of a tag for the new unit at a Sam's Club (with a placeholder price). Reports on Android Central and The Verge also mention hardware spotted at Staples locations, with one person actually succeeding in buying one. All of that follows a listing on the Staples website and one Japanese buyer apparently receiving one early by accident. According to the tags and receipts, the new units are scheduled to go on sale the same day as the Android event, and at the same $249 price of the current 16GB model. Now that the alleged Sony Nexus phone has been exposed as a fake we don't know if there will be any surprises left, but if you want to buy anything from Google's brand then patience (or at least shopping around) is probably your best strategy.