I've always purchased genuine Hakko for my Hakko knock-off. The supplied Aoyue were awful, night and day compared to the Hakko's.
Don't want to wait and sometime cannot wait when there is a need, usualy I load up as many type of tips as possible. To save, I went for the used original T12 tips that the Japanese factories discard way prematurely due to the strict QC. They are good enough for my occasional use of the weird tips. As usual, when there is sale volume, there are clones :-)
Where do you find the used tips from Japan? I don't think I've ever seen them anywhere.