There are advantages to buying from a breeder, as well as rescuing. Naturally, I advocate rescuing because you are choosing to be part of the solution, rather than part of the problem. However, I will do my best to provide an unbiased list of pros and cons for each so that you are able to make your own decision.
Buying from a private breeder
You get to choose the color, gender and age of the animal.
You are getting a glider that has (hopefully) an extensive and healthy lineage.
You get a support system from a good breeder who wants you to call anytime you need (of course, most of us are willing to take your calls just as enthusiastically anyways).
If you are going to breed the glider, it is important to get it from a private breeder who has the lineage of the glider. Otherwise, your babies will not only be worthless (money-wise; they could never be truly worthless), but may also carry genetic weaknesses or diseases that you have no way of knowing about.
Note: large scale breeders do not carry the same advantages. Most simply mass produce plain gliders in a back room with no regard to lineage or handling the baby, which leads to a skittish and possibly unhealthy companion.
Rescuing a glider
Save a life today! Spread the word!
You are saving a homeless, possibly abused glider from a horrible fate.
You are deciding to be a part of the solution instead of the problem, as long as you don't breed them.
They are often cheap or free- and with gliders being as expensive as they are (up to $5000, in some cases), this can be a big deal.
Most of them are every bit as sweet as breeders' babies, even if they require a little more to gain their trust.
It is easier to get an entire glider family, and often the families have a joey IP or recently OOP. If that is not the case, you will find that many males are already neutered- no smelly boys!
Some rescue gliders have special coloring- not all of them are classics!