They only have a few old stuff. I will tell if you anybody want Chaosium's Superworld supplement they have about two each of an adventure and a companion on one of the bottom shelves. The store is packed with all manner of games and miniatures. With more time I went through carefully and found a pack of HUGE graph paper. FOUR double sided 21" by 32" sheets. Note the graph itself is 21" by 32" the sheet is slightly bigger. It made by SJ Games and it great. I am going to share two of them with Tim of Gothridge Manor.
You want the mega dungeon, I will give you the mega dungeon with these.
In addition I finally found a copy of the Dungeon Tiles Master Set: City. All I have is the wilderness set to complete the run. It pretty good and has a mix of scenery tiles (furniture, table, etc), building geomorph, shady part of town tiles, sewer tiles, and city wall tiles. The box is also used this time depicting a roof top area.
Once again my dungeon skill came in useful in navigating the NYC subway system. Although I did screw up the return trip by getting on the express instead of the local. I also put my new kindle to use and found a bead store a few blocks away from the game store. Boy there are a lot of people in Manhattan.
An interesting thing I encountered was when I was making a transfer and had to go up an escalator. The ceiling was really low I could have touched it if I stretched. Well it was so low that when I looked ahead it looked like I was level and everybody was leaning forward. When I neared the top it looked like it was dipping down.
It was extremely disconcerting and at first I thought I must have been tired from travelling. But I looked down and then up again and there it was again! So it got me thinking whether this would work in a dungeon. Basically have a staircase going up fairly steeply but have a really low ceiling. When people enter describe how now everything is level but you are leaning forward walking across a zigzag floor. With a gradual slope before the actual stairs I bet it would be a plausible trick.