S.P.
Best of luck to you both! What a joyous decision. I adopted my beautiful daughter in 2009 from Armenia and it is the best decision I ever made!
Adoption is expensive. I don't think most agencies are dishonest, but it is a business even when non-profit and it is pricey. I would recommend checking out Yahoo! groups for adoption groups. I belong to one that is specific to single moms, but I"m sure they're there for couples. There is a group (not sure it it's Yahoo!) that checks agencies specifically, so you might research that.
All the best to you.
And yes, foster-to-adopt is also less expensive but again a little chancy. I also know of people that have done that successfully.
I would recommend looking on line, researching and making the choice that works best for your family.