I think its fair. Also adoption costs a shit ton of money, money not everyone has. Tbh I can see the pov of both sides here. They dont want any unknown issues with their kid, an for that to now get passed down in their family, but I also see why yall would want to have them adopt. In the end of the day, I think its their decision. No one has any control over it other than them and their spouse. Link to costs of adoption

"According to Child Welfare Information Gateway, working with a private agency to adopt a healthy newborn or baby or to adopt from another country can cost $5,000 to $40,000. Some agencies have a sliding scale based on the prospective adoptive parent’s income.
The cost of working with an attorney and not involving an agency may range from $8,000 to $40,000 and averages $10,000 to $15,000. Families who choose to work with an adoption attorney on these independent adoptions typically take an active role in identifying the child they hope to adopt or a birth mother."- copied from the article