Sure copper is expensive, but so isn't the snap together aluminum. As others have said, stay away from the plastics, other than maybe PEX.
Copper is a good heat sink. Keeps the air in the line cooler. It has antibacterial properties also. So you won't be spraying germs out of your airline if it gets infected.
Copper is pretty easy to put together, I learned to sweat pipes when I was a teen. It gives you nearly unlimited options because all the fittings have been around for decades, none are going to disappear off the shelf anytime soon.
To do it 100% properly the lines should be brazed, but I've never seen that in a shop. This prevents the airline joints from melting if a fire breaks out in the shop.
Copper is very durable, if you hit it with something at most it will dent, but not leak. The advantages of an aluminum snap together system is if you reconfigure your shop often. Then you can pull your system apart and use it again more easily than copper.
The best way to put a system into a shop is a loop. Use 3/4" for the main loop. It should start and end at the compressor. This gives two pathways of air to feed your tools. Then do 1/2" drops or feed the quick disconnects right off the main loop.
Drops are a better idea for water. Have the 1/2" line go several feet below the fitting and end it with a ball valve. This way the condensate has a place to go other than out the connector into your tool.