With Clip Studio, you have an entire box of art goodies on hand to play with.
I think the low price confuses people and makes them think this is just an introductory tool for beginning artists and teens who can't afford the big boy toys. Clip Studio is the real deal and is used by real professional artists like Tracy Bishop, Fiona Staples and more. I've found it to be invaluable for my work. Give the free trial a shot (on the official Manga Studio website) and see why artists are making the switch from Photoshop to Clip Studio, especially for their inking and drawing needs.
The product is great. I got it after getting Corel Painter and prefer it for digits drawing. I like Corel Painter, but it doesn't allow much in the way of drawing, as it says in the name, Painter. It's for digital painting.