Source Robot Parts

Sourcing robot parts seems to be difficult and expensive. 

Ideally I there would be a physical store that I could go to 

At a high level where to source Robot parts? 

Either (1) Online or (2) Physical Store (3) Build Myself

Physical Stores:

• Consumer Electronics Stores
  • Best Buy
• Hardware stores
  • Ace Hardware
  • Home Depot
• Auto Stores
  • Grainger
• Other
  • Japan – Akihabara 

The benefit for going to a specific store is that I can find the part and see it physically
However it doesn’t seem like there are many such stores around

Online Stores: 

• SuperDroids Robots: https://www.superdroidrobots.com/
• Robot Shop: https://www.robotshop.com/
• Robot Realm: https://www.roborealm.com/links/robot_stores.php
• Pololu Robots and Electronics: https://www.pololu.com/
• The Robot Market Place: www.robotmarketplace.com

The benefit of online stores is that I can source the parts from really anywhere
The downside is that I don’t know truly what I’m buying because I can’t hold it physically and there are shipping costs so if I want to split up my purchases over time then I will waste money through shipping. Additionally shipping the parts will take some time

Build Myself: 

The other option is to build the parts myself
I could buy a 3D printer and build specific parts
However, it will take time for me to learn how to use the 3D printer.

Additionally, 3D printers and the filament for the 3D printer are expensive. 

Additionally I may need to buy CAD software as well for the 3D printer and learn how to use the software. 

Therefore, given the time and the cost for 3D printing it may be better to just buy these from someone else.