If they are filming a show then it will be packed. Otherwise its only slightly busier than any normal pawn shop. And if they are not filming it is highly unlikely you will see people from the cast....I think filming the show is the only time they work there anymore. They're all fairly wealthy now. Even Chumley's net worth is estimated close to a million dollars.
Most of the things they sell are just souvenier chotchzkies denoting the show: mugs, tshirts, shotglasses with the show name on it. Whoopy! I dunno...if you are a hard core fan then go for it...but otherwise its really just an overpriced souvenier shop with a few overpriced pawned items.
Oh, and its a safe walk in the daytime...but its also a pretty long walk. I'd pay the $2 for the bus ride.