There seems to be lots of questions about shopping in Russia vs Shopping on the Ship vs...
It seems like all of the ship tours and a number of private tours stop here - if they stop for shopping:
Next door to this (as of Jul 2008). The store is to the left.
The store is good sized with quite an assortment of arts and crap and I doubt any Russian has ever shopped there. A lot of the things a typical tourist might buy are well beyond the means of the average Russian.
I don't really shop, but think the prices here might have been similar to the ship. Beware that they give away free samples of Russian liquors and vodka. The tactic reminds me a little of the art auctions on the ship. I can tell you the most expensive vodka (Imperial) they sell was (I think) about $50 and I saw the same product at Sam's Club back home for $23 !!!!!
Some people indicated that the stop near where the ship docks sell some of the same items that the ship does, but for about 1/4 the price!!! I didn't check it out, but it is definitely worth looking into. There is a sign in the Russian immigration building the shows the way.
As for street vendors. You can definitely bargain with them but of most tours, the tour guide keeps you moving, so you won't have much time. If you see something you like and it is worth (to you) have of what they are asking, be prepared to offer them half in a take or leave it offer. You will see them selling the dolls and all kinds of stuff. I was going to buy one of the hats with lots of Soviet pins in it on the way out from a museum, but we left from a different door and I missed the opportunity. There were asking $20 for the hat and I'm sure it could have been had for $10 or less.