Have known about Beadalon Spool Tamers since they first came out. However, I've never bought any before. The spools of Beadalon jewelry-making wire I've used for 18 years...always come with a wide, clear plastic, wire keeper on them. It flexes enough to just slip it on and then it stays pretty tightly around the spool. It isn't a complete circle, so there's a gap to pull out what's needed each time while keeping the rest from unwinding.
You'd think that the makers of coil-building wire could easily put one of those on each spool when they make it. Wouldn't cost them but maybe 2-3 cents.