Unless you find a great deal from a source that you will not be using in the future, I recommend that you measure and order just what you think you will need.
I ordered most of mine from Aircraft Spruce and Stein Air. There are numerous opportunities to order more wire when you order other items and then save shipping costs. I think that I have placed more orders with Aircraft Spruce than any other vendor in my life. I use the wishlist on their site. Just keep adding items to it until I can justify the shipping costs.
This wire costs $3/foot. I know that you can use cheaper styles of wire for certain uses but I just used the 400 for all.
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2019 Dues Gladly Paid