DragonLancer said:
Its not the monetary value that I consider, its the value of it being a magical item. I view such things as being priceless really.
I also do not like the "magic as technology" aspect of some campaign worlds. You can't just walk into a weaponsmith's and buy a +3 longsword. You would have to find a wizard willing to spend the time and effort to make one, or craft it yourself. Anyone who has a magic item is going to damn well keep it.
So a +1 magical longsword basically could be traded for ten million gold pieces, becaue it is essentially priceless?
Does it take a wizard a "priceless" amount of effort to make even a simple item such as that? Even if you increase the prices 10-fold, there are still going to be items that aren't all that expensive or difficult for a wizard to make - like the aforementioned +1 longsword. Or is there only one wizard in the world and do his efforts to make that one long sword take fifty years and nearly kill him, and now it is the only magical weapon in the land?
At some point, unless you have something like the above, economics dictates that there WILL be items for sale somewhere and the price will be reasonable, not 10 million gold pieces for a +1 rusty dagger.
Of course, if you truly do have a rare magic system like that where even the simplest items is worth more than ten kingdoms combined, you would start to ask yourself - would anyone really trade even one kingdom for it, when a regular army with regular swords would be more than a match for the hero with his +1 longsword. In other words, sometimes, things are worth far less on the market than they cost to make. Which means it is rather uneconomical to make them - but once they are made, they are rather cheaper than you would expect. Sort of like the fact that it can cost a huge amount of money to build a house in a wooded, swampy area, but once you are done, the cost to clear the area and make it suitable for the house may actually exceed the value you could get for the house on the market by a rather large factor - there is no economic rule that says someone is willing to pay a certain price for something in any ratio related to its actual cost.
So, really, how rare is magic? Could you could the number of magic weapons on one hand in the entire world?
And as for "damn well keeping it" - what if the said owner of that +3 longsword slips and falls off of a cliff. His possessions are then found and end up on the market - or even better, they are sent back to his 67 year old grandmother, who has no use whatsoever for a sword, magical or not. But she does need money to live out her retirement. So she sells it. I'm sure I could think up a thousand other such scenarios. An item, magical or not, is out there in the flow of commerce. And everyone has their price.