
While adopting is not necessarily stress-free, I can't imagine it being more "invasive" (or expensive) than undergoing months or years of fertility treatments. The home study was pretty much a non-issue for me (although some agencies are much more thorough and require more writing and answering of personal questions than the one I used), and while the paper chase is a pain in the butt, it's doable and truly not that intrusive.
The fact of being single is not necessarily an issue. I know many single women who have adopted internationally and domestically. Domestically there aren't any more hoops to jump through, but you have to be selected by the birthmother/parents. Given the vagaries of why birthparents choose who will be given the opportunity to parent their child, I'm not sure that being single is actually a handicap. Internationally, whether being single is an extra hurdle depends a lot on the country.
I won't lie. Adopting, from Guatemala in my case, was harder than I expected it to be, but not because it was intrusive or invasive. It was because of the waiting and the lack of control. But those are issues you'd face with ongoing fertility treatments or egg/sperm implantations as well.
