Buying wire and cable can be difficult mostly because wire is usually made with copper. Copper is a commodity publicly traded on the stock market which makes the pricing on wire and cable very volatile. So distributors and manufacturers have to check the pricing on copper every day to make sure their pricing is correct.
I work at a wire and cable distributor as a sales person and customers will call for pricing today and I will have to call them back with a new price tomorrow because copper went up or down so much. South Wire stocks most of their THHN wire and electrical wire because customers need it so often. Even if the wire is in stock the price can still change because South Wire owns it and copper is worth what it’s worth.
The electrical side is the most difficult because of the amount of copper. There isn’t much else that makes up the wire or cable. The insulation is over the bare copper and that’s about it. The electronic side has cables with insulation, shielding and jacket that add to the pricing. The strands are also tinned copper and there is sometimes a drain wire that all get added into the cost of the cable instead of just copper and insulation.
Portable cord is also much easier to price due to the rubber jacket, fillers and heavy insulation. It is an outdoor cord used to supply power to tools and machines on a job site. The one conductor power cables are just about as tough as electrical wire because they are just bare copper strands and the rubber insulation. However, welding and DLO cable are much more flexible and have a more rugged jacket to think about which can alter the pricing.
No matter how you try to work it out you will need to pay attention to copper if you have to buy wire and cable in the near future. No one will be able to tell you if it is better to buy now or buy later because it’s the same as predicting a stock increase. The idea is to watch it and make your own educated decision to buy now or wait a little bit longer.