The alternative is to learn how to administer the AVAYA system yourself, then you won't need anyone to migrate your users. tlpeter is suggesting you do the migration in larger batches, as I am sure if you did a department at a time, they would not charge you $95 for each user. They are probably charging based on the time it takes, it will take less time if they are doing a larger group of users.
Mitch
AVAYA Certified Expert