well i just finished a loooooooooooong reply but somehow it got deleted, oh well. personaly i would pass on them. especialy if they are bfg's. personal experience in the tire industry has left me suspicious of retreaded light truck tires. the heavy duty versions of LT tires are another matter. unless they are a product of a local retreader, they are likely to be poor quality imports from a company that has questionable retreading procedures. ie: a company who would cap a poor quality cassing for export. if they are imported they are more likely a "hot cap" this is an older procedure. the new tread rubber is attached to the cassing ussing high temps.
a "retreaded" or "rebuilt" tire has the new tread rubber attached ussing a combination of chemical reaction, heat and high preasure kilns.
for the most part retreads are not the ideal tire for a high flex invironment. if you plan on ussing these tires off-road a lot and at a low preasure the twisting and flexing would eventualy break the bond and the caps would start to lift on the edges.
unless these tires come with a good waranty i'd stay away from them.
if you'd like more details on the retreading process or how a tire is inspected for retread or just more info on tires in general let me know and i'll do my best to dig up all my literature from the companies i've worked for(goodyear, bandag, oliver-all retread/new in the heavy truck department)