The printed parts on marketplace sites are mostly the same thing: minimum-viable PLA, printed at maximum speed, by sellers who will never see the application and bear no consequence when it fails. For decorative items, fine. For functional parts, you're buying a lottery ticket.
What you can't get from a marketplace listing: material verification (is that really ASA?), application judgment (should this even be printed?), revision (it almost fits), and accountability (it broke in a month). All four are the actual product when you buy from a real shop, here or anywhere.
The infrastructure argument matters too: every functional part bought locally keeps fabrication capability alive in your region, and capability is what you'll want nearby the day something genuinely important breaks. Buy the lottery ticket for the dragon figurine. Buy the boat part from someone who sails.
