Honestly, these pyramid scheme so-called "gambling site" are a scam and only the site owner is real winner.
They start at a low amount, and rely on Person B buying the lot from Person A  (note: site owner does not have to make the any investment) and the unlucky Person X loses his entire amount (which can be rather large) and the site eats that amount. Honestly the hosting and w/e costs nothing compared to just taking lots over a period of a month.