For this post let's assume the DM allowed the creation of this new magic item.
Ring 1
The books state you can add metamagic to items without needing the feats but that there cost would still increase as if the level of the spell did. So you take a incantrix with the forge ring feat. Incantrix prepars metamagic at one level lower than everyone else so it would allow him to make metamagic items cheaper than everyone else. I believe you can also stack metamagic feats as longs as you have the levels. (For instance a double empowered fireball. Empower is normally +2 to level. For incantrix it would only be +1. This would allow him to empower mage armor 8 times for a +20 to ac.) So make a 8 time empowered continous True Strike ring.(+100 to hit) A munchkins dream.
Ring 2
Ring of Unlimited Wishes. Sure it would cost 500000 xp just for all of the wish spells needed and it's market price would be at least 6 million but hey it's worth it.
Ring 1
The books state you can add metamagic to items without needing the feats but that there cost would still increase as if the level of the spell did. So you take a incantrix with the forge ring feat. Incantrix prepars metamagic at one level lower than everyone else so it would allow him to make metamagic items cheaper than everyone else. I believe you can also stack metamagic feats as longs as you have the levels. (For instance a double empowered fireball. Empower is normally +2 to level. For incantrix it would only be +1. This would allow him to empower mage armor 8 times for a +20 to ac.) So make a 8 time empowered continous True Strike ring.(+100 to hit) A munchkins dream.
Ring 2
Ring of Unlimited Wishes. Sure it would cost 500000 xp just for all of the wish spells needed and it's market price would be at least 6 million but hey it's worth it.