The phrase "last dime" means the very last bit of money or the final amount of money that someone has, usually referring to the small amount that is left after all other money has been spent. Full definition
When a man loves God Spend his very last dime Tryin'to hold on to what he needs He'd give up all his comfort Sleep out in the rain If God said that's the way it ought to be (religion.blogs.cnn.com)
The parties haggled over every last dime; what if there are cost overruns? (canadianbusiness.com)
Too many founders worry about negotiating the last dime on the valuation instead of realising that it won't really matter if they are able to build a large successful business. (techcircle.vccircle.com)