That's how I got started, as a teenager.
Couldn't afford to buy the proper supplies, but I could get copper wire scrap from house construction sites.
What's left of my life now is too short to deal with base metals.

I love using scavenged wire when I can find it. I like the feel and color of copper wire, as well as the complex patina it develops, so regardless of perceived value it's my favorite.

try a city dump or junk yard. if you ask nicely, often they'll let you root through industrial garbage in search of cool bits and bops

Don't know what size you use, or what they have available, but try finding someone who works on the technical side of a phone company. They have the coolest colors of coated copper wire. I've only seen it in very large bundles and didn't get my hands on it to play with any, but it's beautiful and they throw tons of it away! I would talk to farmers who are putting up fencing, construction companies, and even electrical stores and animal supply stores, let them know what you are looking for, and see if anyone has anything. Also, I would post it under the "wants" in your local freecycle group. It's amazing how much stuff you can find on those.