Topband: Copper wire source?

[n4uk@mindspring.com (n4uk@mindspring.com)]

         I want to add another 18 radials to my vertical to get it to 48. I 
have been using 12 and 14 au thnn insulated copper purchased locally in rolls 
of 500 feet.  Anyone know where I can get something similar in a roll of 2000 
ft that won't cost me an arm and a leg? Reply direct to me please. 73, Ken , 
N4UK