I thought you found a supplier? What happened? Coz last time you advertise in Garage sales about gliders for sale.

This are the few sounds suggies make.
http://www.sugarglider.net/sounds/sounds.php

And I would suggest you do research on their diets and needs as well, they're not like dogs. Suggies have more complicated diet than dogs and they need more attention too. Besides, they're nocturnal so you have to be sure you're able to stay awake till late night to play with them.

Had you done your research on how to take care of Sugar gliders? What they need properly, what kind of commitment you need to give them? What kind of food they eat, their behavior, their maintenance budget, cage size, whats the difference between male and female behavior and biological characteristics like smell, size How to bond with a glider? How long does it take for a joey to be independent after out of pouch.....etc, you name it.

After this only consider whether you wanna buy him or not.

No offence bro, if you wanna take in such a adorable creature i believe you wanna give it the best right? taking in a sugar glider is like taking care a 3 year old kid. if young joeys then like taking care a baby. heh...
Anyway, good luck on your research and have fun.

Cheers