Blades can be expensive, but ordering a 3 or 5 pack online can be a much better deal. I purchased a 3 pack of Diablo carbide pruning blades in 12 inch size for $24 ($8 each). They last a long time relative to cheaper blades. They generally come in 6 inch, 9 inch and 12 inch lengths. You can get bigger ones, but I don't think they make much sense. The tool isn't strong enough for the longer ones. I did some clearing out and cut lots of brush, a couple trees over 40 feet tall, and cut up roots with it. The carbide blades aren't effected much cutting down in the dirt. I did use my most worn blade for that just in case.
So that is another thing. You can get blades that cut metal. Either thin or even up to supposedly 9/16th inch metal plate. I have not used those, but I have cut thin metal. You can get demolition blades that cut 2x lumber and nails you encounter. You can get fine tooth blades for smoother cuts on things you are building. You can get diamond coated blades for masonry and that sort of thing. They are more versatile than the stubby chain saw, and safer. If you do need a blade change it takes like 5 seconds using no tools which you won't be able to do with the chain saw. Let the chain saw get into the dirt a few seconds and it needs sharpening.