DOn't know of any card shops, but if you like autographed memorabilia, there is a shop in the Miracle Mile Shops in Planet Hollywood called Memorabilia International. They have both current players plus HOF autographs, but their prices are kinda all over the place. But they did have great prices on Ted Williams autographs. A signed 8x10 photo authenticated by PSA (and Green Diamond, the Williams' family company) was only $100 or $125. A signed bat (also PSA / GD) was only $700. Both those prices shocked me for being in Vegas, where if you have ever been to Field of Dreams they have cool stuff, but priced 2-5x higher.
There are also autograph signings at different places. Pete Rose signs pretty much every day in the Forum Shops in Caesar's Palace (think he has moved from Field of Dreams to a shop called Antiquities). And doing an internet search, I see that Dick Butkus is signing today at Field of Dreams. And, Memorabilia International usually has a few boxers signing each weekend, and once a month it looks like they have Joe Montana (looks like he will be there on the 28th and 29th though this month).