what does the following quote mean? (explain)

DOOLITTLE. What is middle class morality? Just an excuse for never giving me anything. Therefore, I ask you, as two gentlemen, not to play that game on me. I'm playing straight with you. I ain't pretending to be deserving. I'm undeserving; and I mean to go on being undeserving. I like it; and that's the truth. Will you take advantage of a man's nature to do him out of the price of his own daughter what he's brought up and fed and clothed by the sweat of his brow until she's growed big enough to be interesting to you two gentlemen? Is five pounds unreasonable? I put it to you; and I leave it to you. (2.273)

Also expland on the idea of Doolittle thinks of himself as a different species of poor person; his comments make it clear that there is more to society than an upper, middle, and lower class. There are, it seems, many different classes within each group.