In addition to cost, the problem with the storage solutions to which you linked is stuff constantly falling off/behind the shelves.

Your most practical solution to the full use of this corner pantry would be shallow shelves on the back and sides, leaving you room to step into the closet

http://imged.me/img/

and/or

either create a door that is/has storage "shelves" in the inside of it that, when the door is closed, fits into the place in which you'd step when the door is open; and/or

create a tall narrow storage box/cabinet that fills the space you'd leave for stepping into the pantry -- wheeled and weighted at the bottom.

You could start with a wheeled dolly

(https://www.uline.com/Product/Detail/H-3750/Totes-Plastic-Storage-Boxes/Tote-Dolly-Steel-20-x-14-x-6?pricode=WA9608&gadtype=pla&id=H-3750&gclid=EAIaIQobChMIw5vr-fTd3AIVyFcNCh3p2ASxEAQYASABEgIQ-fD_BwE&gclsrc=aw.ds)

that fits your space and build a cabinet to set in it or

buy/build the cabinet and add the kinds of wheels intended for tool boxes that can hold enough weight for what you want to store in the cabinet.

http://blockislandtransportation.com/tall-media-storage/tall-media-storage-cabinet-glass-door-doors-large-leather-ottoman-oversized-tufted-low-square-coffee-table-rectangular-upholstered-furniture/

Thanks for you ideas suezbell but this is not a walk in pantry.. this is a corner base cabinet (only 36" high)

You might be better off simply voiding the corner, and make the 24" drawer stack wider.

Consider not adding any shelves other than the bottom/floor of the cabinet. You could use the cabinet for storing only those items you can stack or put in a plastic container that can be stacked on other plastic containers that are large enough so they can be fairly easily reachable.

It could be a place to stash a plastic cake cover and/or dish pan or dish drain or a large plastic strainer or plastic serving trays -- items you could reach the edge of and lift out rather than smaller items you'd need to crawl into the space to reach.

Another thought: what room is on the other side of that wall -- any chance it is a closet or hall that would enable you to just close off this corner w/a faux door from the kitchen side and reach that cabinet space from another room?

Exterior wall is on the other side.

AnnKH interesting idea.. but I need as much space as I can get. I'm thinking DH may have to get creative and customize something.

What do you mean your cabinet people don’t know ? Are they the ones that designed the kitchen ?

Yes they designed the kitchen, however all of their options are made for a rectangle blind cupboard (not one with an angled back like ours).