Currently, an adoption from China runs about $16-18K. Adoption from Guatemala was around $25K for my friend who just completed one, although some are more. There are some countries that are cheaper--Haiti comes to mind, where I understand it is possible to spend around $9-12K. You can adopt from Russia or Ukraine independently and spend less than you would for an agency adoption. It is a lot of money, no doubt. But, consider that many people spend over $20K on a car and it's no big deal.
We adopted from China twice. We raised the money the hard way. We saved. We went into what I call "austerity mode," meaning we cut out ALL non-essential spending. We stopped eating out at all, including no coffee, snacks, lunches, etc. (It was amazing what how much we spent on this and we didn't eat out all that often.) I cook from scratch. We don't have any expenses for frills like cell phones, long distance carriers, caller id, cable TV, etc. Each one of those things doesn't cost much per month, but it all adds up. We stopped spending money for entertainment and relied only on the public library and free stuff. We bought practically nothing that we couldn't literally live without. We drove ancient cars. When I would start feeling deprived, I'd think "Which do I really want more--new shoes or a child?" No contest.
I found the Tightwad Gazette to be very helpful (from the library, of course

). I don't do everything the author does, but it's the mindset that was important.
In both cases, we managed to come up with the money in about a year. We don't have big salaries--dh is a teacher and I'm a librarian. It was harder for the second one, since we have daycare expenses for the first, along with all the kid costs. Keep in mind that you don't have to have all the $ in the bank to start. Most agencies don't require most of the money up front--if they do, that would be a red flag anyway. You pay during the process, with most of the fees toward the end.
Lots of people take home equity loans if that's an option. We don't like non-mortgage debt, so we saved instead. Also keep in mind that there's a $10,000 tax credit that you get after the adoption is complete, and note that it is a credit, which is way better than a deduction. So, some people borrow from relatives and pay it back with the tax credit.
Best of luck. It seems daunting, but it sure can be done.