Think of it as the odds like horse racing at the bookmakers back home, some 2,3 digit numbers that's sought after this cycle will get the price that reflect their odds,
on underground lottery, some thai bookies wouldn't even take certain 'hot' numbers for certain months, their odd calculation is all based in superstition of course, but there's volume to back it up, underground bookies will see the volume of bets coming in and increase the price or remove it from sale all together if they think too many is betting on them, how the punters got their number is hardly any of their concern, but even then when certain shaman or monks has been giving out good numbers for a particular long streak, they might get a hit put on them for costing the bookies too much