welcome to the (very slow) adoption board. there will be other ladies who will chime in here and who have more experience than me on these topics. sorry about your failed FETs. IF is such a drain.
not sure about costa rica. i visited there and asked a local whether adoption was an option and as i understood that you have to be a resident. i am sure your family can find out. i would be interested in knowing as well. what a great country.
i don't know about international adoption but i know a little about domestic and learning more everyday. we are likely going to go through catholic social services and the coordinator at our local branch said 2-4 years wait for an infant. we have not indicated that we would be willing to adopt a bi-racial child so that may lessen the wait. the thing i like about CSS is that we can also work with other agencies at the same time. there are two that we are looking at in addition to CSS. CSS bases fees on how much you and spouse/partner earn and have a max of 15K. very nice.
another way that you can go is through foster/adopt with your state agency. we have considered this as well but friends of ours have been waiting for over a year so it doesn't seem reasonable for us.