I'm sorry I can't help with personal experience, but I found some links that may help.
First is ReptileNCritters. who does sell them but is currently out of stock: http://www.reptilesncritters.com/mex...ng-python.html $89.99 isn't a terrible price, but they only sell adult burrowing pythons, so I wonder if they're captive bred or not.
http://www.hoglezoo.org/meet_our_ani...rrowing_Python Just some general info. It says these little guys live around 40 years, so be prepared to keep them for a very long time.
http://www.eastbayvivarium.com/virtu...mexburrow.html East Bay Vivarium also has one for sale. She's $150, but only a year old and captive bred.
http://www.redorbit.com/education/re...283/index.html Just a little more info on them.
Sadly, I can't find anybig articles on them or any in depth info. Maybe you could email East Bay Vivarium and ask about theirs?