Iceman, I volunteered while at southeastern and it was all paid for and I wasn't grounded. We parted ways a couple of months later and I had to turn equipment in or buy it for $1000. I am no longer on machine. I will say, I wish I still had it. Even though I am sleeping nights now, I can see a big difference.
My understnding is they (SEFL) are asking (firmly) drivers to take sleep study, but it is not required. If your DOT docter requires it later, you will be on your own. That is rumor, but from pretty good source. Hope that helps you.