I have made magic items quite rare in my own campaign world, sure I have run campaigns in which there are 'those kind of shops' available in every major conurbation and even in some of the smaller ones, in which a character can go and outfit themselves in a vast array of splendid (proscribed, game breaking, meta-level) items, if they have the coin. However, this time around I decided that was not to be the case.
Those items that do exist in my own campaign world fall into a number of catagories, each designed to lend power where needed, drain the wallets of the party and add an air of excitement and mysticism. I also make use of 'quality items' that can add bonuses to various tasks, i.e., A Superior quality saddle that adds +15 to the Ride skill or a high quality Scimitar that adds +10 to OB. These 'quality items' do not hold the full benefits of their magical counterparts, for example they are definitely easier to break and they can't harm those creatures that require magical weapons to damage them, but they do add to the skills and compensate for the lack of true items up for sale in my world.
I mentioned categories for the items we do use; here's a rough outline:
One shot deals: Herbs (I have limited these to 'real world' plants). Rune papers, potions and other one shot deals that are relatively easy to create by skilled spell users. Alchemical potions (something I have created myself to add flavour to my campaign world, replace some of the herbs I have taken away and allow the players access to some of the one shot deals that may turn the tide of an adventure. Hopefully I will be getting this to The Guild Companion in the near future for you all to take a look at). It is possible for some of these items to be purchased but of course it would depend heavily on the availability of the resources at hand. I introduced a little trick into my own alchemical potions system to limit sale of such things, I made the
usual shelf life of the potions just 1 hour (must be consumed within 1 hour of manufacture).
Player created items: There are some professions that can create their own items relativly easily, those that come to mind immediately include Druid Staff, Wizard Staff, the various Tartot Mage items and of course my very own Staff of the Magi, featured in this month's Guild Companion.
The one thing I do here to limit some of the power of these items, is insist that Power Point multipliers are not available, the spell adder option must be taken in all cases.
Minor Artefacts: Originally I had hoped to make all of the magical items in my campaign feel very special, Each would have it's own background story, intimate description and array of powers, however without taking on the guise of Stalin on a bad day, I knew if I went too far i would upset my players with the limits I would impose on them. As such 'Minor Artefacts' were born. All of my players are made fully aware that magical items are at a premium in our campaign and so it didn't take long before the background options tables were considered an easy chance to own an all powerful item at the very beginning of a character's career. I toyed with the idea of limiting the items to 'one shot deals' (as above), but then hit on something I had read many years ago (Johnn Four's Role-playing Tips mailing list, I think) about magical items that grow as the character grows (levels up). So every 3 or 5 levels these minor items now grow in power, from the +1 spell adder ring, to the +1 adder that casts Light 10' when the character is in darkness, to the +1 adder, that casts light and now emits 'Sudden Light' the first time the wearer is stunned in combat (per day). Contrary to my original idea of limiting magical items, I have given a little more power to them here, but it has also given them a hell of a lot more flavour. The overall effect here though was to allow my players the sense that although items are hard to come by, when you have one, it's useful and will get better as you progress.
Set Items: OK, so I stole this idea directly from some of those nasty computer games, however if slots in very nicely with my idea to allow magical items to progress in a way that is not linked to the level of the user. This method also allows me to create interesting back-stories, introduce new adventures and give the players a feeling that the items they do manage to procure or not of the static variety that would need replacing at later levels. Without going into too much detail right now, a character in my campaign began her career with a +10 scimitar (background option), I promptly gave it a name a created a background for it (that the character would have to discover). The sword is a part of a set of three items which also includes a shield and a helm. Each item has it's own abilities, but when used together other abilities (and higher bonuses) are gained.
True Artefacts (or Relics): A world low on magical items and I'm talking about perhaps the most powerful items in any campaign? Yes, low on the availability of magical items does not mean I have to be low on power. I absolutely love these things. Each with it's own background, personality, array of powers and of course, will. Could you walk into 'one of those' shops and buy the One Ring? Well, I suppose you could if it allowed. These items are game changing, not so much there for the use of the players, but more so for the use of the GM in the weaving of his tale. In my current campaign, which has been running for almost 3 years now (mean character level around 14), the party has come into possession of 3 relics; one that will guide them through a vast quest in the distant future but has been laying hints and tips of what is to come for the last 2 years (real time), one which contains the soul of a defeated enemy which will come back to haunt them one day and one which they think they are using right now to solve a chain of events but in fact are being used by to create said chain of events.
Hope this helps
