Southeast Michigan here - slightly north of Windsor, Ontario. I have about 1000 SF of decking, portions built in 1984, 1994, 2005. Did them all with a rented post hole digger and a couple bags of Redi-mix each. The last section was done with sonotubes. All are still rock solid. It wasn’t that expensive - and probably just a day or two to auger the post holes, pour and set the posts.

The decking and railings cost way more than setting posts.