You'll find that there are agents who charge 20k plus, and basically they bribe a corrupt immigration officer and pocket 10k. If you're going this illegal route, better to go straight to immigration and bribe them yourself😁
I do not condone this practice as it makes requirements harder for those who do it legally.
Citizenship is obviously easier if married, in any country. Not sure why you recommend going for PR rather than Citizenship, as if he is not married, he has to get PR first. If married, Citizenship is the easier, cheaper, better option by far.