The Idea of making weapons rare is an interesting one, but would probably be more acceptable to more people if specific weapon types are made rarer or more expensive that others, or if you make certain weapons rarer depending on wich part of the world you are in.
for instance- a basic spear is nothing more than a pointy stick, and a quarterstaff is even more basic than that- it stands to reason that a weaker person could do a reasonable amount of damage with a quality made spear, but a quarterstaff would be- and is easier to make, find, yet it takes some skill to use one properly- meanin that anyone could bash around with one, but after a little training and it could easliy match a group of well trained swordsmen- though if they ever DO get a hit in it sould be far more devastating.
another weapon that could be deadly- but may take more training, and would be pretty easy to find and use- would be the basic bow, -though Im really not sure what the plans for missle combat are .
so basically I agree that SOME weapons should be made rare, a sword or solid warhammer would and still do cost a small fortune in this world. but bows and staves, basic spears and clubs, were weapons that wouldnt be found out of place in any commoners home, and might not do the potential dammage of more expensive weapons, but in the right hands could be devastating and cheap