I wouldn't say that camera stores are as common as Starbucks by any means, but 2 of the biggest---not necessarily the cheapest---are BIC Camera and Yodobashi Camera. They have numerous branches in Tokyo/Yokohama/Kawasaki.
There is a big Yodobashi in Akihabara (also called Akiba now) and also in Yokohama at Nishiguchi. Others branches may or may not have as big of a selection. One BIC Camera branch I would not recommend is the one in Ginza---poor selection, always packed, and shabby service in my opinion.
Yodobashi lists that lens on their site for about 69,000, if I remember correctly. I have not actually seen one at the shops yet, but I haven't been seeking it out either. If I were seeking that lens, I would try either the Akihabara or Yokohama Yodobashi first.
Fujiya camera in Nakano is a worth a try... Usually quite a bit cheaper even considering no duty free offered compared to the larger chains.
Take the Chuo line from Shinjuku towards Nakano, get off there, I think it's the 'south' exit (the one that doglegs, you'll know when you get there). Turn right out the exit, where there's a large taxi rank, and you'll see a mall.
Head into it, taking the first right between the fish shop, and an octopus ball shop, heading into the ally. Head down until on your left, you'll notice a shop front with camera posters, and yellow coloured motif. Bottom floor focus is Canon and point and shoot, with a little nikon gear, upstairs (head around the right side of the store to go upstairs) focus on medium and large format, and nikon gear.
They usually have a large range of second hand lenses available.