Depends on quality of her. If she's not very vibrant and pretty brown, maybe $300. If she's very yellow and bright, I'd easily spend $600+ if not more for an almost breedable pastel.
It would take a lot of dough to persuade me to sell my pastel female (she's posted in the thread about graded pastels). Therefore, I'd also be willing to fork over a lot of money for a female pastel of her size and quality.