Actually its from Merberry tails. Amanda Avery makes them and its a latex tail. She sells her work for about $550-650 I believe but it depends on any extras you might add to it.
You can find her on Etsy or Facebook by searching Merberry.
She makes very pretty tails but the time between the order and recieving is 4 to five months generally, she might be getting faster now (She just hired an assistant) but I can not say for sure.