It largely depends on how much you need. If it's only a small amount, it might be worth it to D-Y-I, but if you need a lot, then you have to take into account how much your time is worth to you when you calculate any savings achieved. Take the cost of the wire and the spreader material, then add that to what you feel you're worth per hour multiplied it by how many hours you think it's going to take. My suggestion: figure the longest possible time you think it will take--then double it. Projects always take longer than you expect.
I'm betting that if you use my calculation method, you'll decide to buy. I concur with trying to find the line used if you can but even new may make more economic sense.