The only way I can see someone making any kind of money at 5b a g locally is with stolen electricity. 600w led lights on 12 hour cycle use 1kwhr plus every 2 hours. 4 or 5 baht a kwhr from thai electric for rates. Math doesn't add up. Great growers could do say 1 kgm per light.
Or it's old stock being dumped to recover partial investment.
Or it's washed bud.
5b a g for indoor makes no sense even on a commercial sized grow.