I'm not sure why you would want to buy the Jones XR's... they are the worst tire I have ever had.
I have a set in excellent shape in my garage. They probably have 60-70 miles on them. I was going to put them on my girlfriend's bike since she doesn't leave the pavement, but I'm not 100% sure that her bike can handle the 2.20 rear without the deraileur rubbing. If they don't fit or she doesn't like them, you are welcome to them.
Not available mail-order AFAIK... must be purchased from a local shop... they keep the prices high that way.
Regarding the other post about them not being so good, I don't know, but I was thinking about trying the Jones ACX's some day. They have a more aggressive looking tread than the XR.
I've heard good review's on the ACX's, but the XR's just don't suit my riding style at all... they may be perfect for the original poster. I had a thread about them a while back in the tires and wheels section, but I can't find it anymore.. They don't seem to have too many fans.