I have never purchased a knitted bag but I have knitted bags in the past and really enjoyed making them.
I've made knit and crochet bags and sold them at a small boutique.(for reference they sold for around $40-$50) Now I just make them for friends though and for myself.:shame: They are so much fun to make. I've done felted bags and those are my favorites to make. If you are thinking of making things to sell in my experience scarves are much faster/easier to make and sell more quickly. HTH