You should look into Earthdawn (if you haven't already) because in that game there are no real mass produced magic-items (other than small charms and stuff) and no generic +1 swords or anything like that. Each magic item has a name and a history. While some are purposefully made, they tend to go on and become more than they were originally as the deeds of their wielder(s) help to empower them more. Also, you may find a magic sword that basically acts as a regular sword until you "unlock" (learn, really) its first piece of information. (And subsequently attach a "thread" to it, which is a game mechanic that can be altered or dropped easily.) Then, as you go and you learn more about the sword, it gets better and better, and often has some special abilities that pertain to its original design/use. That way, the character doesn't have to drop the +1 sword when they find a +2, they just learn about it and gain experience that they use to increase the weapon itself. This helps with the money thing - no selling magic for big bucks when they rather keep it - and gives the GM a way to motivate the PCs - who wants to just give up on the item they spent the last 5-10 years game time using and learning and have gotten it all the way to a +40 Broadsword with an additional unbalancing crit of 1-less severity and the ability to detect undead in a 500-foot radius, only to start over with a new weapon/item?