(Retro)Gameshopping in New York (and Washington, Boston)

[Moosmann]

I`m in New York City next week Friday for sightseeing and holiday. I stay 10 days here and I also make additionally at least a daily trip to Washington and Boston for sightseeing reason. To another day, I drive somewhere (area still consider).

1.) Any other recommended Shops for New Gamesoft except Gamestop, Best Buy and Toys `R Us ?
Which shops or branches from Gamestop, Best Buy and Toys`r Us have good offers (reduced prices) for current Handhelds and Consoles ? I know, Gamestop have mostly not good prices, but maybe a branch have special offers :-)

2.) I already found Videogamesnewyork and the Digitalpress Store for older Classic Systems. Still other shops with games for older systems or just used games for current Systems ?

I have sufficient time in New York, but only a limited time in Washington and Boston, so that i just go to the Shops coincidentally on that away with my sightseeing route

As far as I know, Monday 28. May is a Holiday in Amerika. Are really all stored closed on this day ? Is the big 24h Post Office in NYC open on this day ?

Greetings Markus