1. sell button is back - yay
2. in a moderate armor you gain enough money to buy new items and save it for the expensive stuff and even with one expensive item you gain money in the long run
upkeep-system makes the game more realistic... being a knight was very expensive which you could just afford if you were a landlord or something
Ok so how did a central asian nomad, with only a tent and two goats to his name, afford a full horse archer set? My bow should earn me money as I used it to shoot down prey and bring in the bacon. Same goes for my horse, horse milk, hair products, using it to deliver letters etc. I also heard a rumour horse urine was useful in some ways, at least to a nomad. One somewhat unbelievable one is the use of horse urine in gunpowder manufacture (I don't think this is true). How does your stock typical bog standard medieval Western European use horse urine? Waste not want not.
The average nobody who made the rank and file in various central asian hordes owned several of these high endurance ponies. Horses were plentiful and inexpensive to them, while other products were more desired. Tea etc. Same principal at work when you see those sub saharan medieval kingdoms exchange gold for what is considered useless trinkets by Europeans. (By the way, we need some Medival African equipment. Some had very nice chainmail.)
Horses are only expensive if you look at it from a Western European point of view (eurocentrism ftw). Hay and feed costs money, but grass is free and the horse helps a nomad earn money. Mount and blade has never been a Euro simulator which is why I enjoy playing khergits and Sarranids, until servers started putting up Nord versus swadia non stop. Ughhh.
In any case it is not really realistic. Balanced perhaps, realistic probably not.