Drug Crimes, Substance Abuse Accepted plea

[jgjg]

My grandson just accepted a plea for 11 drug traf. and 1 rackateering in New Mexico, plea 10-50. This was his first criminal arrest, found with very little drugs and only about $100 at arrest, no weapons, no violence. Info obtained through phone tap--given 275,000 bond making bail impossible and also the cost of an attorney. He was told by court appointed attorney that if he didn't accept plea he would get at least 18 years because they would then use the school zone (not a school or yard--a few feet into a soccer field. He was told that the judge will probably give 10 due to good record. Attorney has never really heard his side. Only saw twice--a short while when he first took case and a quick visit to offer a plea. This is in New Mexico Is this possible or likely? If not, what can he do? Also can you ever contest a sentence if you take a plea? Can you fire an attorney at this point and would this be a good move.