For breeding purposes I could care less about the level of white. Low whites will throw just as high white babies as anything. Even a Het Pied will throw nice whites while a pair of high whites can throw low whites just as easy as anything.
I paid $1250 for a 2010, 960g female in Daytona last August. She reached 1800g no problem and was bred this year. Hatchlings were going for ~$600- $700. She has ovulated and should shed soon.
What year is she and what is her diet? If she's a 2011 she is eating good and probably a good deal. If she is a 2010 or older I would pass as she is probably a picky eater or a mouser at 900g. For comparison my 2011 Pied is 1150g before eating last night. I have other early 2012 morphs at 600-900g as of now. A 0.1 Super Pastel Daytona pickup from last year as a hatchling is 900g now.
There is always a story behind why someone is selling off a 900g Pied girl that will likely go this fall.