UPDATE Jan 8th 2023; WOW so much traffic on this solution all of the sudden? Then I saw it's leaving gamepass soon. So here's the best updates/tips I pulled from the comments to help you in these final days.
Unfortunately it sounds like, for some players, this becomes bugged and may require a 2nd playthrough.
You have to play the story until a notification will pop up that says the shop is "fully stocked"
A method, that DOES NOT COMPLETE THE STORY, supplied by
Epidote6: "I Recommend trying to play through to the Muttropolis and then playing that over and over for bones to buy stuff. Do not complete the story. Just get far enough to unlock muttropolis then collect bones there over and over to buy all the locations instead of unlocking them through the story." Thank you to Epidote6 for this.
User
REDWINGS05 reported unlocking all but one location through the story. Then purchasing the last location/ToD from the shop as their final purchase. Others reported this worked for them as well.
I personally played the game naturally unlocking levels and times of day through the story/photo requests then going back and buying the remaining items after finishing the game. I didn't care for some of the film packs so I didn't buy all of them until I finished the game. User Shadowmask12 confirmed they did this as well. Some items can be given from tasks/objectives, some items won't be in the shop until you do these tasks.
Others have reported finishing the story locks this for them and they get stuck with a 2nd playthough, so I suggest trying the non-story complete methods first.
From my observations of comments either methods MAY cause people some problems. Other folks have reported this worked fine for them. So your choice really, again lots of players are having trouble with this while others have no problem at all, it's unclear why.
Thanks to the helpful comments from this great community, I mostly wrote this thinking it was just a list of items, but it turned into a buggy mess. Good luck out there.
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List of Camera parts from shop:Black & White Film Pack
Flashbulb
Earthy Film Pack
Extra Film
Stylish Film Pack
Pixel Lens
Artsy Film Pack
Monochroma Film Pack
Candyshop Film Pack
Fisheye Lens
Focus Lens
Far Out Film Pack
Slow-Mo Lens
Flare Lens
Stripe Lens
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THANK YOU to users;
burpeesDaily
Epidote6
Malboa77I
I Like Drinkin
Archer Spense
REDWINGS05
for their helpful contributions.