How is $4 too pricey?

Some reviews have people asking how is the full version worth $4? A pack of 100 flash cards costs $1. Some flash card apps are free. But those flash cards can only be used once and those apps are crrrraaaaap. When you are looking for an app that you will DEPEND on to learn vocabulary, equations, languages, etc. this is going to be an app you will use for the entire life of your phone. Not to mention the creator gives major updates that somehow reinvent the (flashcard) wheel every few months. Angry Birds will only give you a month or two TOPS of fun for $1 and who cares about their updates. So if you are using this app on a daily basis or even a monthly basis, in the end this app will have cost you nothing in comparison to the four measely dollars you invested. I dont understand how people pay $5-$10 on Fifa games and Madden games every year when they give you nothing in return but a few afternoons and two plane trips of entertainment. This isnt just another flashcard app. This is the CREME DE LA CREME of flash card apps and Will always be one of my main 4 apps on my iphone.

AAJohn54 about Flashcards Deluxe Lite, v3.1