Thank you so much for the review. The thing you mentioned about the attack not working is probably because the dash only works if you are moving. When you stand still, the dash attack doesn't work. (I actually noticed that too while playing).
Also, yes you are the first one to notice that, in fact, my shop's items prices are not correct! I'm very sorry for that. When I was testing the game, I changed all of the item prices to 1 and I completely forgot to change it back before uploading the game! I was devastated when I found that out after the submission time was over :( . I will immediately fix that once the reviews end.