Whether or not the Parents are entitled to reimbursement is a complicated legal question. The notice to the District must meet certain procedural requirements. I would NEVER recommend a unilateral placement without working with a special education attorney or a seasoned special education advocate. If Parents' notice is not sufficient, they are not entitled to reimbursement.
Even if the request if procedurally valid, a unilateral placement is financial risky. Reimbursement is only warranted if the IEP at the time of the unilateral placement does not provide FAPE and the out-of-district placement does. Reimbursement might also be confined if the District later offers an IEP that does provide FAPE. BEFORE a parents decides to unilaterally place their child, it is very important to a comprehensive case analysis by an experienced special education attorney. This is best way for you to optimize your chances of recouping your expenses.
If you are considering a unilateral placement, contact the North Shore Massachusetts Law Firm of Lillian E. Wong.