I'd say it depends on the mushroom types you want to grow.
Shiitake I would buy plugs because they are, in my opinion, a more finicky eater so therefore harder for me to propagate at home.
Garden Giant/Wine Cap, since you can't find them in the grocery store here, I started with a kit, got familiar with the smell, look, and taste before setting it free. That was a safety measure for me and worked out great.
Oysters I can find in the
local grocery store at a reasonable price and have had excellent luck propagating them on boiled
cardboard and then adding boiled
wood chips. So, I wouldn't buy a kit for that, just some mushrooms that look fresh and save the stems.
I'm considering inoculating my "woods" with morels. Because they are so expensive in the grocery store here and I'm not sure the variety or ease of propagation from mushroom, I will probably just buy spores, or whatever is recommended,
online once I'm sure there's nothing already growing there I can confused them with. They are difficult to confuse though compared to some other types.
I will never grow white button types. They look way too much like poisonous varieties and there's a saying: there two types of mushroom hunters careful ones and dead ones.
Good luck!