NICE THREAD!
About making a MOD about it:
If you want to make heavy armor and horses a little rarer in battle, add random events, a small chance every day, that the horse disappears or gets lame ("dies", "gets sick", "has accident, breaks leg", "has grown older, you sell it", "has been stolen at night!"), or that armor disappears or deteriorates ("takes rust",
"breaks", etc). Plate could deteriorate more often than other armours (on the ground that mail can be fixed manually).
Nothing is forever!
Same could go for weapons, especially lances and arrows, maybe? -- edit: a chance after every battle that you can't find/reuse arrows, and/or that lance broke?
I would not remove stuff you can buy, or merchants, as this would impoverish game variety.
Rather, it is quite easy to almost enforce the rule: "cannot spend more than lvl*lvl*lvl dinars on a single object".
For example, make a new event automatically triggered every few seconds. It does this: if your money is larger than
the lvl-cubed limit, it is downsized to that limit, and the difference is saved in an extra variable (a remote virtual "bank account").
If current cash is smaller than the limit, cash is augmented to the limit, "withdrawing" the money from your "bank account" (if is there is any left).
Not perfect, because one could still sell a lot of stuff and buy the expensive thingy in the same go, but quite a good approximation.
(I've noticed that many RPG computer games just turn the players into "object feticists", where you stick to your favorite equipment as if it was part
of your character...)
