I went into both websites and saved them. The one you have to buy in large quanties, but the Marathon does carry 100% quilting and embroidery thread and the price for a single spool in US dollars appears to be excellent. Don't know if it would be worth the shipping to order one spool to see how it works.
I am normally an Aurifil thread person. I love their threads and I have trying to find them discounted. My embroidery threads are the OS whatever by Berninia. Only because when the lfs closed I was able to buy a huge amount between 30 and 40%. Fortunately knowing sooner then most what was going on I was able to get as many as I could before they were all gone.
But I would be extremely interested in attempting to save some money on threads.