Okay, I hope it's okay to post a link to a website that I found where you can buy cheap thread (including serger cones) and other sewing supplies too (I saw they had zippers that seemed reasonably priced).
I found this site because last year I had ordered some Guttermann thread in a co-op and I'm starting to run out but I don't want to pay the big bucks for it at Joann's. My machine ONLY likes Guttermann, and I know several of you have said the same (I'm looking at YOU Mr. Rocketpants!

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Anyway, I checked with the girl who ran the co-op and she gave me the site she ordered through. I was very surprised that their prices are great even without putting in a major wholesale order!
If you follow the link you can buy COLORED Guttermann thread in 1,076 yd. spools for $2.49! And shipping is a flat rate $4.99. If you buy the same yardage at Joann's you can only get black or white and it costs over $8! The only difference between these two is these do NOT have those fancy thread locking spools, but the thread is wound onto a simple plastic tube.
Wawak Sewing Supplies
Okay, I hope that helps someone else.
Sunshine