So this wig site I found is having a spring sale right now. And by spring sale, I mean all of their wigs are under $40 (most around $35), including the super long ones. They offer free shipping if an order is over ¥5000, and say they can get things to my apartment within 18 hours of receiving the order.
Hannah and I just ordered two wigs from them, and we got them this morning; (one thing I love about Japanese delivery services: you can choose what time of day/what day you want things delivered so you can be sure to be there) they're super thick (tons of wefts), and they're nice fiber too.
They're sold the way most wigs seem to be in Japan: unstyled, in various lengths. The one exception seems to be that they have long curled wigs. but with unstyled bangs and such. However, this also means that the fibers are heat resistant, and don't tangle easily.
If you'd like a wig from them, please let me know, and I'll work something out with you regarding payment and shipping out of Japan. Also, this post is public, so if you know anyone who wants/needs wigs right now, feel free to pass this along!
Edit: as far as I know, the sale goes on until the end of April, but it may go on fo longer, but if it does, idk how much longer.