Hi Ginger,
I am sure there are others who are better equipped to answer this but I can share what I know from my own experiences.
Facilitators are not licensed (not that I know of anyway) or regulated and in fact, are illegal in some states. You will need to check your state laws to find out what is legal in your neck of the woods. A facilitator for the most part is a person who links potential birthmothers with families who are wishing to adopt.
In order to use the term agency, the person or business must be licensed by the state and therefore there is a body of oversight. Generally, an agency will have more services in addition to the matching of pbmom's and pre-adoptive parents. They may have Social Workers on staff to complete homestudies. Provide counseling for pregnant women, adoptive couples, post placement services, and post adoption services.
The costs of both facilitators and agencies vary greatly so you will just have to search and see what is within your price range. A lot of attorneys use facilitators in order to locate potential birthmothers and pre-adoptive families. So you may be required to pay both the attorney's fees and the facilitators or it may be combined. Kind of like a finders fee. Just depends.
You will most likely find that some people have very strong feelings about facilitators. There some drawbacks and even some ethical questions. Many of the facilitators out there are not counselors nor do they have any formal education or training. There may not be any counseling available or even offered for the pbmom's.
There are some horror stories out there about facilitators (and agencies too I should add). I think there are good and bad in everything and in every profession though so do your research.
We signed up with both a facilitator/attorney team and a licensed agency. We are matched and waiting for the birth of our child (hopefully March 9th!). In our case, the pbmom came to us through the facilitator/attorney and then our agency has an attorney on staff who will handle some of the legals and finalization (included in the amount we paid) . Our agency is also planning to do the post placement visits and post adoption services. It has worked out well for us...so far anyway!
I hope this helps clear things up for you. I certainly don't know all the answers and I hope others will jump in if I said something in error.
Good luck!
T