Are these good deals on bikes? or should i stick with the 150r?

My mom is going to buy me a dirtbike, but i dont know if she wants to spend $4,300 on a brand new crf150r
are these good bikes?

1. http://batonrouge.craigslist.org/mcy/1053944294.html
2. http://batonrouge.craigslist.org/mcy/1043143933.html
3. 2002 KX85, LOW hours, never raced, $1200

or should i stay with the 150r?

my friend wants to sell me his for $3,200