100% I think players would have a much better time if high tier armor was more accessible. My suggestions:
1. Make it mostly culture/region-specific (i.e. Imperials have Imperial, Battanians have Battanian armors, but sometimes there is overlap).
2. Make it available in a reasonable amount of locations, but not all.
3. Have a single town in each kingdom where the best armor for that particular faction is produced.
4. Make it reasonably priced.
5. Have more armor diversity. Some should have better body but less arm protection, more leg less body stats, etc.
Explanations for each point:
1. Specific armors in specific places is already implemented. It's great. But there is so much cross-regional trading in Bannerlord, why not show that through the armors for sale? Maybe a Battanian King was taken to an Imperial settlement in chains by a jealous cousin, and his armor ended up on the market? Who knows.
2. Our troops get these amazing armors. I should able to get it for myself and my companions too.
3. Supremely effective armors should be where the legendary smiths are. It'd make sense for a few towns to have these smiths, but not all. This mechanic would make searching for good armor less tedious, while keeping it rare enough, and add to the satisfaction of finally finding the town where the good smith is. Also adds a bit of world-building flavor.
4. I think it's reasonable to make suiting-up a companion in good armor cost 30k. But not 200k denars. My Palatine Archers can find top-end gear for a few bucks, so clearly it's availiable somewhere at a reasonable price. Note: for the best armors, from legendary smiths, I think that armor should be a tier above in strength and cost. For that, I think somewhere closer to 100k-150k each is reasonable to suit-up the player and their companions.
5. This would make armors feel much less similar. Instead of feeling like you're buying the same things with different looks, you're more likely to really consider your amor choices. This change would also give regional troops more diversity, encourage new strategies, and further enrich the lore/play-ability of the game.
Plain and simple, I'm arguing for what I think is common sense. Give the players things they want. Make the game fun and people will have a good time. This is already a good game, and I think these changes will make it even better.