My guess is Yi Xing, China. An area known for "purple clay" of this color. Yi Xing tea pots are world famous and can be quite valuable. I have a carved relief dragon pot that cost me more than a car payment. The Yi Xing kilns made "production grade" pots for export in addition to or because the high end market was not big enough.
Looking at the rough interior finish, I would guess this is a "production grade" pot, meaning good quality but not a piece that would get a premium price. Anywhere from $45 to $145, in part depending on size. The signature was probable a kiln mark more than an artist's mark. If I was selling, I'd expect the lower half of the range I gave you. But I have not bought or sold any Chinese pots in a couple years.