CD Duplication
If you are on a tight budget and want to print up a relatively low quantity of cds, you'll want to go with cd duplication. CD duplication is the ?cheaper? process which you often see with local bands. The cd uses a cd-r and often the printing is good but not quite as good a major label band printing. Typical prices per disc for cd duplication run in the $2-4 range. Seldom do people print up more than 200-300 using duplication.
It needs to be noted that cd-rs simply don't last as long as the real deal cds. You probably have experienced this. The cd-rs used in cd duplication are not any different than the a high quality cd-r you'd by at your local consumer electronics store. Some cd players still have problems reading cd-rs. Cd-rs are more sensitive to heat and scratching as well.
Overall cd duplication is a great choice for a band wanting to print up 100 or so copies on a limited budget.
CD Replication
Replication is the real deal. Instead of using a cd-r, the cd is actually placed into a mold and stamped with the digital information. This is exactly how the big boys do it. Cd replication plants have a minimum quantity that they will print. Most start at 500 and typically cost about $1000. However, for around $1200-1400 you can come home with 1000 cds. All the 1000 cds for a $1000 ads you see in magazines use cd replication.
If you have plans to need more than 300 copies of your cd, or you just want your cd to look professional, I highly recommend replicating your discs. They will look better and last longer. Per cd, they are quite a bit cheaper, but you stand the risk of having a basement full of cds for the rest of your life though.