Honestly, it comes down to the customer paying whatever they're willing for a product that they are expected to be knowledgable enough of prior to the purchase. Basically, if you're a smart consumer, you'll know what you're paying for and value it at whatever you deem it worth. Taleworlds grants every opportunity, not to mention nearly full-game demos, merely with level caps, to have a taste of what you're in for. If you feel the need to complain about this particular product here, go out in the world and find out for yourself just how unfair it is.
I paid the $30 a few years ago for the original m&b. I played the demo, liked it, and paid the price to keep going. I heard about f&s coming out so I gave the updated original another spin and can still see how I got hooked to it back when I was playing it. That being said, you don't hear me *****ing about how it's worth $4 now. When a company makes an effort to display and explain new features, it's entirely up to you.
Taken from the sticky:
"It uses the Warband engine (with some alterations), so it will look like a mod. The difference is the professional level of work, the large amount of content with fully fleshed out singleplayer and multiplayer, which includes a new game mode dedicated to commanding. Ultimately, it's up to you to decide whether you want to buy the game or not."