In my Tutorials/Kits that I sell, I send practice wire with the instructions as well as Argentium Sterling Silver Wire. The more practice, the better it will be when you use the more expensive wire. There are places where you can get practice wire made of nickel, it washes well and lasts.
Hope this has helped answer your question.
Gail
http://Gembeadboardsnmore.artfire.com
http://bead-space.com/gjones92126

copper is a good alternative for learning on and as a bonus it's really pretty too :o)
You can get round copper at the hardware store and Brandywine has square in dif gauges so you can make all the gorgeous pieces you see here for very little money. Then when you feel ready you can buy some silver, it's not near as intimidating once you've been playing with wire for a little bit :o)

Dana

A little more information that I forgot to add:
There are different gauges of Sterling Silver if you are using a lot of 18 gauge which is big for most jewelry wirewrapping, yes it would be very expensive. If you are making a pendant with 21 guage wire for wrapping a gemstone, then using 1/2 round wire for the bindings. That is not as expensive - 1/2 round you get around 40 or more feet per ounce of wire. the 21 gauge you get around 19 to 20 feet per ounce. I save the special precious metal wire for the perfect project.
When I have practiced with copper or nickel wire and am ready to wrap a precious gemstone, I want the really pretty Sterling Silver or Gold filled or even Rose Gold filled wire. The Gemstone or Cabochon color with being held against the different wires shows me what would look elegant with that particular stone or gem.
Have an awesome day!
Gail
http://Gembeadboardsnmore.artfire.com

I often use copper wire for practise or to work out a design. It is very cheap to buy (which is good, because at the moment, a lot of my stuff gets dumped as, "No, this isn't working!") Of course, I use copper for final, 'to wear' pieces too.
I also use silver plated copper wire, which costs a little bit more but not much, if I want to see how a design would work out in silver.
Real silver is reserved for when there's a chance that I know what I'm doing!