My local library (in the UK) will fetch me a book from any participating library in the UK or Ireland and loan it to me for a month, for two pounds and fifty pence (a bit under four dollars at current exchange rates). They'll extend the loan if I ask and the owning library doesn't mind.
Over the past year, I've had books from university libraries up and down the country, big chunky tomes from the British Library, and books from regional library systems that happened by chance to hold a copy of whatever I was looking for. Basically, any time I come across a book I want to read, I pitch over to www.worldcat.org and see if any library in the UK holds a copy. If someone does (and sometimes it's just one library), I make an inter library loan request and a week later it's in my hands. I've been shot down twice; once when the book was subsequently found to no longer exist in the single library listed on worldcat, and once when the university library said it was in too high demand and would I mind asking again in July when the demand would have dropped.
I've had technical manuals, obscure novels, expensive books that I wanted to get my hands on for a few weeks to see if I'd use it or enjoy it enough to buy my own copy, some really niche books on the shipping industry, stupidly expensive books of compiled data, all sorts. Two pounds fifty for a month's loan is an absolute bargain.