For years I have used Maxilock (3,000 yds) from Wal-Mart (color selection extremely limited) for $1.94, and from
Atlanta Thread ($1.85 for same cone) - - I am not affiliate or advertising - I have just bought for years from them and a great color selection - and I haven't had problems with any of it in serging, sewing or even test sew outs in my embroidery machines. :D
Mary