Don't know when you need your Tetra wig by, but Almost Legit Cosplay
is currently taking wig commissions. I messaged them a while back asking how long it would take them to make the wig and how much it would cost, and they responded that it would take around a week (not including shipping time to Colorado) and would cost around $150 for them to use the exact same wig that they used (including shipping fees). They also mentioned that they wanted to remake the wig and would post a tutorial of how to style it that way if they did.
If you don't have that much money, Miharichu-Emi on DeviantART also made a nice-looking Tetra wig
and showed me a WIP photo
of it showing how she styled the thing.