Hello, I'm nagol68

Gidday Logan from NewZealand ( aka Downunder )

Nonferrous ( non magnetic ) metals, particularly Copper & Brass pay the best $$
Then Aluminium & Lead & Stainless Steel
And scrap sheet steel, whitewares & such, pay almost nothing.
Heavy Metal Insize ( less than 3 feet long ) is still worth a few $ but Steel takes up more space.

Find your local Scrapyard & find out what they pay & how they class the different grades.
Any contamination of the metal ( with other metals or glass/plastic etc ) drops your return quite quickly.

While some grades are bought as mixed metals, like Copper & Brass radiators. And Aluminium & Copper radiators ( from fridges & dehumidifiers & AC units )
Electric motors & transformers have their own grade & pricings.
Aluminium has about.5 different grades, domestic Ali, Extrusion, Cast Ali etc etc. They cant be contaminated with Steel or it really drops its price.

Check local Laws regarding opening up fridges & letting the CFC gas out. Its a big $$ fine in some places.
Fridge compressors have about 2Lbs of Copper in them.
Old microwave ovens used to too, but now most of them only have Aluminium wound transformers.

Having a decient truck to haul metal is very very handy. And your knowing about how to sell the Cats is a good start.
I get the 8mpression that students do throw out a lot of good scrapmetal items, they tend to get fumped at the end of the years, and brought again at the start of the new year.
A couple of members here have made good $$ getting, cleaning & fixing, then selling at the start of the year to new students.