Because the host has a very big advantage of determining the game by always being the first at the buying line during an auction (if he wants), and being able to buy all the available goods before the other players can, why not change the concept.
I don't think the current concept conicides with the original game to begin with. And so you might be suggesting to change the concept based on the assumption that what is happening now is the correct way, which is not.
- just like selling to the shop, buying from the shop should be done simultaneously if there are more then one persons to buy at the same price. Buying from humans should be done one by one dividing the goods over the people buying.
In the original game, if multiple people meet the line then the person with the lowest amount of cash gets priority. With that in mind, would you still suggest the same thing?
- is it an idea for the shop to increase the price it is selling at during an auction if the shop notices the realtime demand is high (for example: when people are still running up at the selling line, the price gets pushed up a little per each transaction?)
Yes, that is an interesting idea but I am not sure how well it would play out in a turn by turn concept.
- what about the fact that you can push the price for for example a land auction so high that noone else can buy it, and then back off not buying it yourself. Does the minimum price need to drop?
This is working the same as the original game. It can be used as a way to prevent the plot from being sold. However, while this may appear to be an advantage for the player who did it, in reality it may in fact be a disadvantage, since he is allowing the plot to be obtained for free on the next land grant... and he is not necessarily guaranteed to obtain it himself.