I was recommended to look at J&L Industrial by a friend (who sells the Keyless Chucks for those who bought one) as a place to look for HIGH precision live centers. They seem to have a very wide variance in price but some of the modest priced ones look like they are worthwhile.
http://www.jlindustrial.com/endeca/searchResults.jsp?Ntt=live+center&Ns=list_price&Nty=1&Ntx=mode+matchallpartial&N=0&Ntk=Keyword+Search
Two in particular peaked my curiosity.
One was their lowest cost center. It doesn't list the tolerance except to say "Close Tolerance" whatever that means but it does have triple bearings which is great for a center for less than $20.
http://www.jlindustrial.com/catalog/product.jsp?id=ECT-64002M&origin=SEARCH:KEYWORD&backtosearchpage=Y#
The other one looks remarkably like the Sorby live center set which runs $100 with the interchangeable points and it is less than $30.
http://www.jlindustrial.com/catalog/product.jsp?id=RTC-49904B&origin=SEARCH:KEYWORD&backtosearchpage=Y
And for those in need of a #7 MT live center with a tolerance of ± .0001" they have one for a little less than $3000.
± .0001"[}

]
http://www.jlindustrial.com/catalog/product.jsp?id=RLC-10367C&origin=SEARCH:KEYWORD&backtosearchpage=Y#
But seriously, those machinists out there, I would be interested in your opinions of the first two for the price.