Topband: Dog fence parameter radial wire

[mstangelo at comcast.net]

I have an inverted L in the trees of my back yard with 30 radials. The length of the radials is 70 feet since this is what I could fit into the existing area. I lay my radials on the ground since the area is wooded and doesn't have much foot activity.

I got my radial wire years ago when surplus wire was cheap. This is no longer the case.

I want to add additional radials and am looking for a suitable wire source that will not break the bank. I'd like to use solid copper wire.
 
I was thinking of using 18 gauge insulated dog  fence parameter wire. Has anyone use this wire for their radial systems?

Thanks in advance,

Mike N2MS