My thoughts are with you, best of luck in your journey. I'm several years ahead of you on that same path. If you ever have questions or want to chat about it let me know.
My wife and I tried to conceive the old fashioned way for several years with no luck. We went to a fertility doctor, got all those tests, and then heard the crushing diagnosis. He recommended we skip all the lightweight stuff and go right to IVF. We did three IVF cycles but they all failed. That was the damn crappiest year of our lives. Your estimate of about 15K per cycle is accurate though sometimes you can find doctors that have shared risk plans where you don't pay as much if it doesn't work. My wife was in a support group with about 7 other girls and IVF worked for all of them though so your odds are good.
After the third IVF cycle we decided to stop and switch to adoption. Like you said, there is only so much money to be spent on this. It took us a year to get into the adoption program and we have now been waiting about 15 months in the program for a domestic newborn. The wait is longer than we thought but part of the reason is that we set the bar pretty high, no drug use or mental illness for the mom, etc. I think the cost will be about 30-35K, pretty high yes but not as much as you had mentioned. Plus there is a tax credit of $11,650 you can get from the government if you qualify, see
http://www.irs.gov/taxtopics/tc607.html.
My recommendation is just take one step at a time. One form, one procedure, etc. The big picture was just to much for us to focus on. And, don't forget yourselves in the process. Take time to just have fun, take small vacations, go to movies, and so on. It is easy to let it all consume you but that doesn't help anything. And, keep up with your hobbies. For me, going shooting, hiking, and screwing around with knives keeps my mind active on other topics. Find what works for you.
I'm getting pretty anxious about our adoption. We've had a few close calls but nothing yet. Hopefully soon.
Good luck to you.
Mark