Inanima, in hopes of being helpful, you must be talking about the XR70 if it's a four stroke. XR = 4, CR = 2. In shopping for a bike for my 6 year old son, I have found that a lot of the used bike sellers are trying to get close to what they paid, including sales tax, so that may account for the high prices you are seeing.
I already have a ride planned for my son with a friend whose son has a dirtbike. That way, I'll be able to tell if my son enjoys the sport before I plunk down the cash for his bike. You might consider doing the same, if possible.
P.S. Take a look at KTM for some alternatives.
"The one thing that unites all human beings, regardless of
age, gender, religion, economic status or ethnic background, is that,
deep down inside, we ALL believe that we are above average drivers."
[This message has been edited by Pete (edited August 07, 2000).]