$4.4 m of net worth puts you in the top 1% by US standards. In the rest of the world (short of Monaco, Luxembourg and Switzerland and the likes), it's much less. For example top 1% in France means a net worth of $2m.
I find it hilarious the notion that the "middle class" would have "hundreds of thousands of dollars" of disposable income to splurge on gambling.
I'd go as far as saying that being in the top 1% in, say, France, puts you in the "rich" class, not the "middle class" and that with a net worth of $2m you do not have line of credits allowing you to bet hundreds of thousands of EUR/USD.
P.S: I was invited at some dude's place where he had this 3 meters high Jeff Koens sculpture (Ballerinas, kinda Jeff Koens' trademark), probably worth millions. He had four house employees serving coffee, cooking, etc. Reading HN I'd be tempted to believe he was actually a poor middle class chap and that only the Zuck and Gates are "rich".