Just no, it will be too op considering owning the shop will allow you to change prices. Gangs will buy up all shops and max the prices out or some random kavala fuck will, leading to the economy breaking.
Make picking metal like lockpicking, you gotta keep pressing the button to gather 1 metal, then press it... Takes more time and removes the ability to afk pick since you gotta press the action every 1-3 seconds to pick a new metal piece.
Yeah this is part of what i don't like, It makes a city look like a shithole. Some parts of my city is so bad id rather have it replaced by a small african village. At least they wont destroy their homes because of stupidity