I am looking for a specific piece and I don’t know if they will have it. Is it any piece or just basic ones like 2x4’s?
At the LEGOLAND California Pick a Brick wall last week (March 9th 2019) they had mostly basic brick shapes. There were some plates, some modified bricks with studs on the side, and a couple of containers had thick rubber wheels, the smallest kind. There was also a container of 1x6x6 panels in white. Nothing else stood out as particularly interesting.
Can you imagine the size of PAB wall to contain every piece? It would be enormous. So naturally PAB brick choice is limited.
Normally shop management decide which bricks they are willing to have on their wall. However there are exceptions:
- some stores have space dedicated to PAM (pick-a-model), with all parts available for such model;
- some stores may have "AFOL choice" bricks;
- there may be shops testing some new bricks choice.
And so on. So chances you find a piece you need are random. If you look for a particular piece - give a call to accessible LEGO stores with PAB or order them online via LEGO webpage or Bricklink.
The management (or the employee(s) they have delegated that to) of each store decides what is in the wall of that store, but they do it from a list of elements somebody higher up, thinks should be in the stores (and having been to a number of stores, I guess it's the same list. at least on each side of the Atlantic ocean).
There's always a selection of fairly standard element It probably don't accurately reflect what's in that wall today, but they can give an idea of what the s, but always also a selection of not so standard elements.
There a website dedicated to listing what's in the wall at each store, but it's only correct if somebody updates it, and as we don't use that in Copenhagen (see below), I've forgotten the address.
In Copenhagen traditionally nobody can be bothered updating that site, but there are a few members of the danish LUG that takes an element from each hole, places them sort of nicely on a table and takes some pictures, that they then share. An old (january 2017, I couldn't find a recent, and this is just to give an idea anyway) set of such pictures: https://www.flickr.com/photos/25179966@N06/sets/72157668755923501
When going on a toy run to any store, the easiest thing to do is to simply call the place up, and speak to a live person. In most cases they want to help you not waste your time or money on a fruitless trek.
The store could be a Target, Walgreens, GameStop, Best Buy, Barnes & Noble, Sears, Walmart, or LEGO Store. Just Google Map the area for a specific store and a list of locations and phone numbers pop up.
Simple say "Hello, or Hey there", and repeat the franchise name, "I'm looking for..."
Either way, if they say they do or don't have it, use this time you have them on the phone to chat them up about new promotions, "Hey LEGO store, I haven't been in there in a month or two, has anything changed?"
So, personally I'm 40 minutes between two stores, but haven't been to one since past November. The last thing my LEGO rep said to me that might help in regard to your specific question about needing a specific piece is, LEGO allowing a store to order their own inventory, which is something great.
It might take a little more patience, and fitness with other store reps that aren't versed in LEGO, but always remember the gas money saved by not driving there on a hope and a prayer.
Check the inventory at your local store (and please update it if it's out of date!) http://www.brickbuildr.com/index.php/all-stores/