Hi and welcome to DB! Formal playgroups here in HK are pretty expensive as you've probably found out already! The way we do it is to send my son just 2 mornings a week so that he gets used to structured activities in time for kindergarten. Other than that we have heaps of playdates during the week. Not necessarily at peoples houses, but even just meeting in playgrounds or the plaza. Most of my friends here I met through Midget Gems. They opened (not sure if they still do it) their playroom every Thursday afternoon for a few hours. No teacher, no class, just playing. Cost was $50 to cover drinks and snacks. They have a website, check them out. Other than that we just went to playgrounds and started talking to people! You can also try the American Women's Association. Not sure of all the details but they should have a website somewhere. And maybe the resident's club does something? Not sure there either, but otherwise there's always the playroom. Good luck!